CN106757349A - Rare earth crystal growth equipment, rare earth crystal growth technique and application - Google Patents

Abstract

The invention provides a rare earth crystal growth equipment, which comprises: a crystal growth furnace; a heating element is arranged inside the crystal growth furnace; an observation window is arranged on the furnace top of the crystal growth furnace; A circulating cooling water system is provided outside the furnace top of the furnace and the periphery of the observation window; an image observation element is provided outside the furnace top of the crystal growth furnace and above the observation window. Compared with the prior art, the present invention arranges a circulating cooling water system outside the observation window at the top of the crystal growth furnace, which can take away the heat transferred to the top of the furnace during the crystal growth process, and provides a suitable environment for installing image observation elements outside the observation window. working environment, and the remote observation of the crystal pulling furnace can be realized through the image observation element.

Description

Rare earth crystal growth equipment, rare earth crystal growth process and application

technical field

The invention relates to the technical field of crystal materials, in particular to rare earth crystal growth equipment, a rare earth crystal growth process and its application.

Background technique

Rare-earth functional crystal materials, as an important medium for the conversion of light, sound, and electricity, can provide high-quality working materials for a variety of important key devices. Rare earth scintillation crystals have the characteristics of high density, high light output, and fast attenuation, which meet the basic requirements for scintillators in high-energy physics, nuclear medicine and other application fields. Rare earth optoelectronic crystal materials can realize the interaction and conversion of electricity and light, and are widely used It is used in communication, aerospace, medicine, geology, meteorology, architecture, military technology and other fields.

The crystal growth furnace produced by the French company Cyberstar is recognized as having the best comprehensive performance, which can realize the whole process of computer-controlled and intelligently controlled crystal growth. However, during the whole process of crystal growth, crystal growth personnel are required to conduct real-time observations to adjust growth parameters at any time. In this process, frequent artificial disturbances will be brought and affect the quality of rare earth crystals.

In addition, there is an observation element above the general crystal growth furnace, which is convenient for crystal growth personnel to judge the melting material in the early stage, seed the crystal operation, and observe the crystal growth process in real time in the later stage, and deal with any abnormalities in time. In order to prevent the observation hole from being affected by the high temperature of the furnace top (the high-temperature melt transfers heat upward in the axial direction), the observation hole is small in size, and the observation hole on such a small area can effectively prevent crystal growth personnel from being exposed to too much heat. This type of upper observation hole has a small observation area and is inclined at a certain angle, so that crystal growth personnel can observe events inside the furnace and the internal temperature field structure as much as possible, and it is convenient to deal with abnormal conditions during the crystal pulling and growing process. However, due to the small observation area of the upper observation element, when growing large-scale high-temperature rare earth crystals, the observation hole of the temperature field structure constructed by the insulation material is opened above the temperature field, that is, the upper observation element can only be used for monitoring, and the observation hole above the furnace is too large. Due to the small size, the crystal growth process can only be observed with the naked eye by crystal growth personnel, that is, the images of the growth process cannot be remotely monitored and recorded. In rare earth crystal growth, this will cause a great waste of human resources. In addition, most of the pulling growth equipment available on the market is general-purpose crystal growth equipment, which requires crystal growth personnel to build a temperature field structure for the crystal to be grown, and there is a lack of special pulling growth equipment for rare earth crystal growth.

Contents of the invention

In view of this, the technical problem to be solved by the present invention is to provide rare earth crystal growth equipment, rare earth crystal growth process and application, and the growth equipment can realize remote observation of crystal pulling furnace.

The invention provides a rare earth crystal growth equipment, comprising:

Crystal growth furnace;

The interior of the crystal growth furnace is provided with a heating element;

The top of the furnace of the crystal growth furnace is provided with an observation window;

A circulating cooling water system is arranged on the outside of the furnace top of the crystal growth furnace and the periphery of the observation window;

The outside of the top of the furnace of the crystal growth furnace and the upper part of the observation window are provided with an image observation element.

Preferably, the observation window has a diameter of 50-80mm.

Preferably, the image observation component includes a camera and a camera bracket; the camera can be rotated through the camera bracket.

Preferably, the image observation element further includes a filter; the filter is arranged at the front end of the camera.

Preferably, the side wall of the furnace body of the crystal growth furnace includes a first thermal insulation material layer, a second thermal insulation material layer and a third thermal insulation material layer arranged sequentially from the inside of the furnace to the outside of the furnace; the first thermal insulation material layer is oxidized Zirconium insulation material; the second insulation material layer is formed of zirconia and alumina; the third insulation material layer is zirconia insulation material.

Preferably, the density of the first insulation material layer is 5.2-3.8g/cm ³ ; the density of the second insulation material layer is 3.5-2.3g/cm ³ ; the density of the third insulation material layer is 1.8 ~0.6 g/cm ³ .

Preferably, the thickness of the first insulation material layer is 1-3.5cm;

The thickness of the second insulation material layer is 1-4cm;

The thickness of the third insulating material layer is 0.5-1.5 cm.

Preferably, the heating element is an iridium product and a Cu induction coil; the size of the iridium product is φ70-140 mm, and the depth is 50-150 mm; the size of the Cu induction coil is 2 to 3 times the size of the iridium product .

The present invention also provides a rare earth crystal growth process, comprising:

a) After mixing the high-purity rare earth raw materials, the mixed raw materials are obtained;

b) under vacuum or protective atmosphere, after sintering the mixed raw materials obtained in the above steps, polycrystalline blocks are obtained;

c) Under vacuum or a protective atmosphere, after melting the polycrystalline block obtained in the above steps in the rare earth crystal growth equipment described in any one of claims 1 to 8, use the pulling method under the guidance of the seed crystal to carry out After crystal growth, rare earth crystals are obtained.

The present invention also provides the application of the above-mentioned rare earth crystal growth equipment in growing yttrium aluminum garnet crystals and/or rare earth orthosilicate crystals.

The invention provides a rare earth crystal growth equipment, which comprises: a crystal growth furnace; a heating element is arranged inside the crystal growth furnace; an observation window is arranged on the furnace top of the crystal growth furnace; A circulating cooling water system is provided outside the furnace top of the furnace and the periphery of the observation window; an image observation element is provided outside the furnace top of the crystal growth furnace and above the observation window. Compared with the prior art, the present invention arranges a circulating cooling water system outside the observation window at the top of the crystal growth furnace, which can take away the heat transferred to the top of the furnace during the crystal growth process, and provides a suitable environment for installing image observation elements outside the observation window. working environment, and the remote observation of the crystal pulling furnace can be realized through the image observation element.

Description of drawings

Fig. 1 is the structural representation of the rare earth crystal growth equipment provided by the present invention;

Fig. 2 is the structural representation of the circulating cooling water system provided by the present invention;

Fig. 3 is a schematic structural diagram of the crystal growth furnace provided by the present invention.

detailed description

In order to further understand the present invention, the preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the invention.

Referring to Fig. 1, Fig. 2 and Fig. 3, Fig. 1 is a schematic structural diagram of the rare earth crystal growth equipment provided by the present invention; Fig. 2 is a schematic structural diagram of a circulating cooling water system; Fig. 3 is a schematic structural diagram of a crystal growth furnace.

The invention provides a kind of rare earth crystal growth equipment, comprising: a crystal growth furnace; a heating element is arranged inside the crystal growth furnace; an observation window is arranged at the top of the furnace of the crystal growth furnace; A circulating cooling water system is arranged on the outside of the observation window and on the periphery of the observation window; an image observation element is arranged on the outside of the furnace top of the crystal growth furnace and on the upper part of the observation window.

According to the present invention, the interior of the crystal growth furnace is provided with a heating element; the heating element can be a heating element well known to those skilled in the art, and there is no special limitation. The heating element in the present invention is preferably an iridium product and the Cu induction coil; the size of the iridium product is preferably φ70-140 mm, and the depth is 50-150 mm; the size of the Cu induction coil is preferably 2 to 3 times the size of the iridium product.

The side wall of the furnace body of the crystal growth furnace preferably includes a first thermal insulation material layer, a second thermal insulation material layer and a third thermal insulation material layer arranged in sequence from the inside of the furnace to the outside of the furnace; the first thermal insulation material layer is zirconia thermal insulation material layer. material; the second insulation material layer is formed of zirconia and alumina; the third insulation material layer is zirconia insulation material. Wherein, the density of the first insulating material layer is preferably 5.2-3.8 g/cm ³ , more preferably 5-4 g/cm ³ , even more preferably 4.8-4.2 g/cm ³ , most preferably 4.5 g/cm ³ The thickness of the first insulation layer is preferably 1-3.5cm, more preferably 2-3.5cm, more preferably 2.5-3cm, most preferably 2.5cm; the density of the second insulation material layer is preferably 3.5- 2.3g/cm ³ , more preferably 3.2-2.5g/cm ³ , more preferably 3-2.5g/cm ³ , most preferably 2.5g/cm ³ ; the thickness of the second insulation layer is preferably 1-4cm , more preferably 2-3.5 cm, more preferably 2.5-3 cm, most preferably 3 cm; the density of the third insulation material layer is preferably 1.8-0.6 g/cm ³ , more preferably 1.6-0.8 g/cm ³ , more preferably 1.4-1g/cm ³ , most preferably 1.2g/cm ³ ; the thickness of the third insulation layer is preferably 0.5-1.5cm, more preferably 0.8-1.2cm, and more preferably 1-1.2cm , most preferably 1 cm.

The invention builds a temperature field structure suitable for rare earth oxides and its matching heating elements in the crystal growth furnace, provides suitable axial and radial temperature gradients for the growth of rare earth oxide crystals, and realizes yttrium aluminum garnet crystals of φ30-80mm (RE:Y ₃ Al ₅ O ₁₂ , RE=Ce,Nd,Sm,Eu,Ho,Tm,Er,Yb) and rare earth orthosilicates (Ce:RE ₂ SiO ₅ ,RE=La,Gd,Y ).

The top of the furnace of the crystal growth furnace is provided with an observation window; the observation window is preferably a wide-angle observation window; the diameter of the observation window is preferably 50-80 mm.

The outside of the top of the furnace of the crystal growth furnace and the periphery of the observation window are provided with a circulating cooling water system, which can take away the heat transferred to the top of the furnace during the crystal growth process, and provides a suitable environment for installing image observation elements outside the observation window. working environment.

The outside of the furnace top of the crystal growth furnace and the upper part of the observation window are provided with an image observation element; the image observation element can be an image observation element well known to those skilled in the art, and there is no special limitation. Preferably, a camera and a camera bracket are included; the camera can be rotated through the camera bracket, more preferably 360°, fully utilizing the advantage of the wide viewing angle of the upper viewing window, and can realize a wide viewing angle of 122° to 154° for the internal environment of the furnace Observation; the video camera is preferably connected to the computer terminal, so as to realize the image remote monitoring function.

In the present invention, the image observation element preferably further includes a filter; the filter is arranged at the front end of the camera. Avoid the strong light brought by the melt temperature higher than 1800°C, which will cause the image to be unobservable.

The present invention arranges a circulating cooling water system outside the observation window at the top of the crystal growth furnace, which can take away the heat transferred to the top of the furnace during the crystal growth process, and provides a suitable working environment for installing image observation components outside the observation window. The observation element can realize the remote observation of the crystal pulling furnace.

The present invention also provides a process for growing rare earth crystals using the above rare earth crystal growth equipment, including: a) mixing high-purity rare earth raw materials to obtain mixed raw materials; b) mixing the above steps After the obtained mixed raw material is sintered, a polycrystalline material block is obtained; c) under vacuum or a protective atmosphere, after the polycrystalline material block obtained in the above steps is melted in the above-mentioned rare earth crystal growth equipment, the seed crystal is formed by pulling After crystal growth under the guidance of , rare earth crystals are obtained.

All raw materials in the present invention have no particular limitation on their sources, they can be purchased from the market or prepared according to conventional methods well known to those skilled in the art.

All raw materials of the present invention have a purity higher than 0.9999 (4N).

Wherein, the high-purity rare earth raw material is a high-purity raw material known to those skilled in the art that can obtain rare earth crystals, and there is no special limitation. In the present invention, it is preferred that yttrium aluminum garnet crystals and/or rare earth normal High-purity rare earth raw materials for silicate crystals.

The invention mixes the high-purity raw materials according to the set ratio to obtain the mixed raw materials. The present invention is not particularly limited to the mixing conditions, the mixing conditions of this type of reaction well known to those skilled in the art can be used, and those skilled in the art can adjust according to actual production conditions and raw material conditions. The present invention is preferably uniform mixing, The mixing time is preferably 24-120 h, more preferably 40-120 h, more preferably 60-120 h, most preferably 80-120 h. The method of mixing is not particularly limited in the present invention. In the method of mixing well known to those skilled in the art, the present invention preferably uses a mixer for mixing. The present invention has no special restrictions on other properties of the mixed raw material, and the properties of the mixed raw material for preparing rare earth scintillation crystals well known to those skilled in the art can be used. The particle size of the mixed raw material in the present invention is preferably 0.05-30 μm, more preferably 0.1 to 25 μm, more preferably 1 to 15 μm, most preferably 2 to 8 μm.

In the present invention, the mixed raw materials obtained in the above steps are then sintered under a vacuum or a protective atmosphere to obtain a polycrystalline block.

The present invention is not particularly limited to the pressure of the vacuum, and the vacuum pressure of the sintering process well known to those skilled in the art can be used. The vacuum pressure of the present invention is preferably less than or equal to 10Pa, more preferably less than or equal to 7Pa, more preferably Less than or equal to 5Pa, most preferably 3 to 5Pa; the present invention has no special restrictions on the protective atmosphere, the protective atmosphere for sintering rare earth crystals well known to those skilled in the art can be used, and the protective atmosphere of the present invention is preferably It is one or more of nitrogen, inert gas and reducing gas, more preferably nitrogen and reducing gas, most preferably nitrogen, argon and hydrogen.

The present invention has no particular limitation on the specific conditions of the sintering, and the sintering conditions well known to those skilled in the art can be used. The temperature of the sintering in the present invention is preferably 900-1300°C, more preferably 950-1250°C, more preferably 1000-1200°C, most preferably 1050-1150°C. The sintering time of the present invention is preferably 12-24 hours, more preferably 13-22 hours, more preferably 14-22 hours, most preferably 15-20 hours. The present invention has no particular limitation on the sintering equipment, and the sintering equipment well-known to those skilled in the art can be used. In the present invention, the mixed raw materials are preferably put into a high-purity crucible and sintered in a sintering furnace.

In order to achieve a better sintering effect in the present invention, it is also preferred that the mixed raw materials are pressed into cakes to obtain raw material cakes, and then sintered. The present invention has no special restrictions on the specific steps and process parameters of the pressed cake, the specific steps and process parameters of the pre-sintered compact known to those skilled in the art can be used, and those skilled in the art can according to the actual production situation, raw material composition and The product performance needs to be selected and adjusted. The pressure of the pressed cake in the present invention is preferably 20-70 MPa, more preferably 30-60 MPa, and most preferably 40-50 MPa.

Finally, in the present invention, under vacuum or protective atmosphere, the polycrystalline block obtained in the above steps is melted in the above-mentioned rare earth crystal growth equipment, and the crystal is grown under the guidance of the pulling method seed crystal to obtain the rare earth crystal.

The present invention is not particularly limited to the pressure of the vacuum, and the vacuum pressure of the sintering process well known to those skilled in the art can be used. The vacuum pressure of the present invention is preferably less than or equal to 10Pa, more preferably less than or equal to 7Pa, more preferably Less than or equal to 5Pa, most preferably 3 to 5Pa; the present invention has no special restrictions on the protective atmosphere, the protective atmosphere for sintering rare earth crystals well known to those skilled in the art can be used, and the protective atmosphere of the present invention is preferably It is one or more of nitrogen, inert gas and reducing gas, more preferably nitrogen and reducing gas, most preferably nitrogen, argon and hydrogen.

Entering the heating stage, the polycrystalline block begins to melt. The melts of yttrium aluminum garnet and rare earth orthosilicate crystals contain different fluid compositions, and after the crystal material is completely melted, characteristic liquid streamlines appear. The liquid flow lines appearing on the melt surface at different times can be clearly recorded by using an external high-temperature camera. Crystal growth personnel can judge the seeding temperature according to the liquid flow line characteristics at different time periods combined with the temperature display, and perform remote operation of the seeding. A single person can complete the entire seeding process, reducing human resources.

The present invention has no special limitation on the seed crystal, and the seed crystal known to those skilled in the art for preparing rare earth scintillation crystals can be used.

The guiding temperature (seeding temperature) of the present invention is preferably 1800-2050°C, more preferably 1810-2000°C, more preferably 1830-1970°C, most preferably 1840-1950°C.

In the present invention, there is no special limitation on the heating process of the temperature-rising polycrystalline block, and the heating process known to those skilled in the art will suffice. The seeding operation in the present invention is preferably performed when the characteristic liquid flow lines (liquid flow lines) appear. Those skilled in the art can understand that the liquid flow line refers to a curve that is tangent to the velocity vector at every point in the liquid fluid field. The appearance of the characteristic liquid streamlines in the present invention is preferably macroscopically, when the polycrystalline block changes from a solid phase to a liquid phase, when ripples appear on the surface of the liquid phase, the characteristic liquid streamlines appear.

In the present invention, after the characteristic liquid flow line appears, the seed crystal is used for seeding operation, and then the pulling method is used for crystal growth, and the crystal growth is realized according to the growth rate and rotation rate calculated by the crystal theory, and the rare earth crystal is obtained. The present invention has no special restrictions on the pulling method, and the pulling method for preparing rare earth crystals well known to those skilled in the art can be used; the present invention has no special restrictions on the process parameters of the pulling method, and those skilled in the art can according to Select and adjust according to the actual production situation, raw material composition and product performance requirements.

The crystal growth rate of the present invention is preferably 2.5-8.0 mm/h, more preferably 4-7.5 mm/h, more preferably 5.1-7.0 mm/h, most preferably 5.5-6.5 mm/h; the crystal The rotation rate is preferably 6-30 rpm, more preferably 8-25 rpm, more preferably 10-22 rpm, most preferably 10-18 rpm.

The present invention also provides an application of the above-mentioned rare earth crystal growth equipment in growing yttrium aluminum garnet crystals and/or rare earth orthosilicate crystals.

By observing the whole growth process of yttrium aluminum garnet crystal in real time. The image of the seeding process was captured, and after repeated adjustments, a suitable temperature gradient was obtained. When the seed crystal just touched the melt surface, it grew slightly, which proved that the growth temperature was appropriate. After undergoing the "necking" operation, the crystal enters the shoulder-shouldering stage. The captured early and mid-stage shoulder-shouldering images show that the size of the crystal is constantly increasing, and the geometry of the projected contour along the growth direction is also gradually changing. The images entering isometric growth show that the geometry of the projected profile along the growth direction remains unchanged compared to the increase in crystal size during the shouldering phase. This function can significantly reduce the impact of frequent human disturbance on the quality of rare earth crystals.

In order to further illustrate the present invention, the rare earth crystal growth equipment, rare earth crystal growth process and application provided by the present invention will be described in detail below in conjunction with the examples, and the scope of protection of the present invention is not limited by the following examples.

Example 1

Rare earth crystal growth equipment is provided: a crystal growth furnace; a heating element is provided inside the crystal growth furnace, and the heating element is preferably an iridium product and a Cu induction coil; the size of the iridium product is preferably φ130mm and a depth of 130mm; the The size of the Cu induction coil is preferably 2 to 3 times the size of the iridium product; the side wall of the furnace body of the crystal growth furnace preferably includes a first heat insulating material layer, a second heat insulating material layer and The third insulating material layer; the first insulating material layer is zirconia insulating material; the second insulating material layer is formed of zirconia and alumina; the third insulating material layer is zirconia insulating material; the second insulating material layer is formed of zirconia insulating material; The density of a thermal insulation material layer is preferably 4.5g/cm ³ ; the thickness of the first thermal insulation layer is 2.5cm; the density of the second thermal insulation material layer is preferably 2.5g/cm ³ ; the thickness of the second thermal insulation layer The thickness is 3cm; the density of the third insulation material layer is preferably 1.2g/cm ³ ; the thickness of the third insulation layer is 1cm; the furnace top of the crystal growth furnace is provided with an observation window, and the observation window The diameter is 55mm; the outside of the furnace top of the crystal growth furnace and the periphery of the observation window are provided with a circulating cooling water system; the outside of the furnace top of the crystal growth furnace and the top of the observation window are provided with image observation elements , the image observation element includes a camera and a camera bracket; the camera can be rotated by 360° through the camera bracket.

Y ₂ O ₃ and Al ₂ O ₃ powders with a purity higher than 99.995% are weighed according to the ratio of Y ₂ O ₃ :Al ₂ O ₃ =3:5, pressed and sintered into a round cake-shaped Y ₃ Al ₅ O ₁₂ polycrystalline raw materials. 5000g of crystal material blocks are successively loaded into the Ir crucible in the crystal growth furnace of the above-mentioned rare earth growth equipment, and the seed crystal in the [111] direction is loaded at the front end of the seed rod. Adjust the observation position and angle of the high-temperature camera above the crystal growth furnace to focus on the center of the melt surface. After the furnace is evacuated, it is filled with high-purity N ₂ gas as a protective gas to heat up the molten material (polycrystalline material block). Using the chemical bonding theory of crystal growth to determine the dominant growth direction [111], the calculated growth rate of Y ₃ Al ₅ O ₁₂ along the [111] direction is 2.5-6.0mm/h, and the rotation rate is 8-18rpm. During the seeding process, the contact between the seed crystal and the melt surface and the growth/melting situation were observed remotely, and the "seed crystal" operation was performed remotely. After repeated adjustments, a suitable temperature gradient was obtained. When the seed crystal just touched the melt surface, there was a slight Prove that the growth temperature is suitable. After undergoing the "necking" operation, the crystal enters the growth stage, and the whole growth process is monitored in situ by using the remote observation function. This function can significantly reduce the impact of frequent human disturbance on the quality of rare earth crystals.

The size of the grown Y ₃ Al ₅ O ₁₂ crystal: the equal diameter is φ78mm, the total length of the crystal is 240mm, and the total weight is 3.24kg. No cracks, crystal quality intact.

Example 2

The rare earth crystal growth apparatus in Example 1 is provided.

CeO ₂ , Y ₂ O ₃ , and Al ₂ O ₃ powders with a purity higher than 99.995% are weighed according to the ratio of CeO ₂ :Y ₂ O ₃ :Al ₂ O ₃ =0.03:2.97:5, pressed and sintered into Round cake Ce:Y ₃ Al ₅ O ₁₂ polycrystalline raw material. 1000 g of crystal material blocks are stacked and loaded into the Ir crucible in the above-mentioned crystal growth furnace, and the seed crystal in the [111] direction is loaded at the front end of the seed rod. Adjust the observation position and angle of the high-temperature camera above the crystal growth furnace to focus on the center of the melt surface. After the furnace is evacuated, it is filled with high-purity N ₂ gas as a protective gas to heat up the molten material (polycrystalline material block). Using the chemical bonding theory of crystal growth to determine the dominant growth direction [111], the calculated growth rate of Ce:Y ₃ Al ₅ O ₁₂ along the [111] direction is 2.5-6.0mm/h, and the rotation rate is 8-18rpm. During the seeding process, the contact between the seed crystal and the melt surface and the growth/melting situation were observed remotely, and the "seed crystal" operation was performed remotely. After repeated adjustments, a suitable temperature gradient was obtained. When the seed crystal just touched the melt surface, there was a slight Prove that the growth temperature is suitable. After undergoing the "necking" operation, the crystal enters the "shouldering" stage, the crystal size increases, and the geometry of the projected contour along the growth direction gradually changes, evolving from the initial hexagon to the truncated hexagon. After entering the equal-diameter growth, the geometric shape of the projected contour along the growth direction presents a truncated hexagon. After the equal-diameter growth, it enters the cooling stage, the crystal image is clearly visible, and the Ce:Y ₃ Al ₅ O ₁₂ crystal grows well.

Growth Ce:Y ₃ Al ₅ O ₁₂ crystal size: equal diameter φ40mm, total crystal length 90mm, total weight 0.42kg. No cracks, crystal quality intact. The crystal emission peak position is located at ~460nm with a decay time of ~100ns.

Example 3

The rare earth crystal growth apparatus in Example 1 is provided.

According to the above process, Lu ₂ O ₃ , SiO ₂ , and CeO ₂ powders with a purity higher than 99.995% were weighed according to the ratio of Lu ₂ O ₃ : SiO ₂ :CeO ₂ =1.195:1:0.005, pressed and sintered into Round cake-shaped Ce:Lu ₂ SiO ₅ polycrystalline raw material. 3400 g of crystal material blocks are stacked and loaded into the Ir crucible in the above-mentioned crystal growth furnace, and the seed crystal in the [010] direction is loaded at the front end of the seed rod. Adjust the observation position and angle of the high-temperature camera above the crystal growth furnace to focus on the center of the melt surface. After the furnace is evacuated, it is filled with high-purity Ar as a protective gas, and the molten material (polycrystalline material) is heated up. Using the chemical bonding theory of crystal growth to determine the dominant growth direction [010], the calculated growth rate of Ce:Lu ₂ SiO ₅ along the [010] direction is 4.0-6.5mm/h, the rotation rate is 2.5-6.0mm/h, and the rotation Speed 10 ~ 25rpm. Remotely observe the characteristics of the liquid flow line at different time periods, judge the seeding temperature, and perform the "seeding" operation. After undergoing the "necking" operation, the crystal enters the growth stage, and the whole growth process is monitored in situ by using the remote observation function. This function can significantly reduce the impact of frequent human disturbance on the quality of rare earth crystals.

Growth Ce: Lu ₂ SiO ₅ crystal size: equal diameter φ40mm, total crystal length 140mm, total weight 1.46kg. No cracks, crystal quality intact. The emission peak position of the crystal is at ~420nm, the light output is 28000photos/MeV@622keV, and the decay time is ~40ns.

The descriptions of the above embodiments are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A rare earth crystal growth device, characterized in that, comprising: Crystal growth furnace; The interior of the crystal growth furnace is provided with a heating element; The top of the furnace of the crystal growth furnace is provided with an observation window; A circulating cooling water system is arranged on the outside of the furnace top of the crystal growth furnace and the periphery of the observation window; The outside of the top of the furnace of the crystal growth furnace and the upper part of the observation window are provided with an image observation element. 2. The rare earth crystal growth equipment according to claim 1, characterized in that, the diameter of the observation window is 50-80 mm. 3 . The rare earth crystal growth equipment according to claim 1 , wherein the image observation element comprises a camera and a camera bracket; the camera can be rotated by the camera bracket. 4 . 4. The rare earth crystal growth equipment according to claim 3, wherein the image observation element further comprises a filter; the filter is arranged at the front end of the camera. 5. rare earth crystal growth equipment according to claim 1, is characterized in that, the furnace body side wall of described crystal growth furnace comprises the first insulating material layer, the second insulating material layer and The third insulation material layer; the first insulation material layer is zirconia insulation material; the second insulation material layer is formed of zirconia and alumina; the third insulation material layer is zirconia insulation material. 6. The rare earth crystal growth equipment according to claim 5, characterized in that, the density of the first insulating material layer is 5.2-3.8 g/cm ³ ; the density of the second insulating material layer is 3.5-2.3 g /cm ³ ; the density of the third insulating material layer is 1.8-0.6 g/cm ³ . 7. The rare earth crystal growth equipment according to claim 5, characterized in that, the thickness of the first insulating material layer is 1-3.5 cm; The thickness of the second insulation material layer is 1-4cm; The thickness of the third insulating material layer is 0.5-1.5 cm. 8. The rare earth crystal growth equipment according to claim 1, wherein the heating element is an iridium product and a Cu induction coil; the iridium product has a size of φ70-140mm and a depth of 50-150mm; The size of the Cu induction coil is 2 to 3 times the size of the iridium product. 9. A rare earth crystal growth process, characterized in that, comprising: a) After mixing the high-purity rare earth raw materials, the mixed raw materials are obtained; b) under vacuum or protective atmosphere, after sintering the mixed raw materials obtained in the above steps, polycrystalline blocks are obtained; c) Under vacuum or a protective atmosphere, after melting the polycrystalline block obtained in the above steps in the rare earth crystal growth equipment described in any one of claims 1 to 8, use the pulling method under the guidance of the seed crystal to carry out After crystal growth, rare earth crystals are obtained. 10. The application of the rare earth crystal growth equipment described in any one of claims 1 to 8 in growing yttrium aluminum garnet crystals and/or rare earth orthosilicate crystals.