CN103951249B - Rare earth ion doped Cs 2liGdI 6devitrified glass and preparation method thereof - Google Patents

Abstract

_The invention discloses a _{Cs 2 LiGdI 6} glass ceramics _doped with rare earth _ions and a preparation method thereof. : 15-20mol%, Gd ₂ O ₃ : 5-9mol%, Cs ₂ LiGd _(1-x) Ln _x I ₆ : 11-15mol%, where x=0.05-0.2, Ln is Ce ³⁺ , Eu ^{3 +} , Tb ³⁺ , Pr ³⁺ and Nd ³⁺ as a rare earth ion, the preparation method is first to prepare P ₂ O ₅ -B ₂ O ₃ -BaF ₂ -Gd ₂ O ₃ -Cs ₂ by melting method LiGd _(1-x) Ln _x I ₆ series glass, transparent Cs ₂ LiGdI ₆ glass-ceramics obtained after heat treatment, Cs ₂ LiGdI ₆ glass-ceramics of the present invention, can resist deliquescence, good mechanical properties, short-wavelength blue-violet light High transmittance, strong output of scintillation light, and good energy resolution. The preparation method of the crystallized glass is simple and the production cost is low.

Description

Cs2LiGdI6 glass ceramics doped with rare earth ions and its preparation method

technical field

The invention relates to a rare earth ion-doped glass-ceramic, in particular to a rare-earth ion-doped Cs ₂ LiGdI ₆ glass-ceramic used as a scintillation material and a preparation method thereof.

Background technique

Scintillation material is a photofunctional material that can emit visible light under the excitation of high-energy rays (such as x-rays, γ-rays) or other radioactive particles. It is widely used in nuclear medicine diagnosis, high-energy physics and nuclear physics experimental research, industry and geology. exploration and other fields. Depending on the application field, the requirements for scintillators are also different, but in general scintillation materials should have the following characteristics: high luminous efficiency, fast fluorescence decay, high density, low cost and good radiation resistance. Scintillation crystals generally have the advantages of radiation resistance, fast decay, and high light output, but scintillation crystals also have the following serious disadvantages: preparation is difficult and expensive. Although scintillation glass doped with rare earth ions is low in cost and easy to prepare large-sized glass, it is difficult to compare with crystal in terms of light output and repetition times, so its application is also greatly limited.

Cs ₂ LiGdI ₆ crystal is a scintillation crystal matrix that can be doped with rare earth ions. Ce ³⁺ doped Cs ₂ LiGdI ₆ crystal has high light output, fast decay, good energy resolution, time resolution and linear response. It has higher luminous efficiency than fluoride crystals and oxide crystals doped with rare earth ions, and can greatly improve the efficiency of nuclear detectors. Eu ³⁺ , Tb ³⁺ doped Cs ₂ LiGdI ₆ crystals also have excellent scintillation properties, and can be used in security inspections, scintillation fluorescent screens and other fields. However, Cs ₂ LiGdI ₆ crystals are easy to deliquescence, poor in mechanical properties, easy to cleavage into flakes, difficult to grow large-sized crystals, and expensive, which affects its practical application.

Contents of the invention

The technical problem to be solved by the present invention is to provide a kind of rare earth ion- _{doped Cs2LiGdI6} glass-ceramic with good deliquescence resistance, good mechanical properties, strong light output, fast decay, energy resolution and time resolution and its Preparation.

The technical solution adopted by the present invention to solve the above _- mentioned technical problems is: _Cs2LiGdI6 glass ceramics doped with rare earth ions, and its mole percentage is composed of:

P ₂ O ₅ : 30-40mol% B ₂ O ₃ : 25-30mol% BaF ₂ : 15-20mol%

Gd ₂ O ₃ : 5-9mol% Cs ₂ LiGd _(1-x) Ln _x I ₆ : 11-15mol%, where x=0.05-0.2, Ln is Ce ³⁺ , Eu ³⁺ , Tb ³⁺ , Pr A rare earth ion in ³⁺ and Nd ³⁺ .

The scintillation glass-ceramic raw material components are: P ₂ O ₅ : 30 mol%, B ₂ O ₃ : 30 mol%, BaF ₂ : 20 mol%, Gd ₂ O ₃ : 5 mol%, Cs ₂ LiGd _0.95 Ce _0.05 I ₆ : 15 mol %.

The scintillation glass-ceramic raw material components are: P ₂ O ₅ : 35 mol%, B ₂ O ₃ : 28 mol%, BaF ₂ : 17 mol%, Gd ₂ O ₃ : 6 mol%, Cs ₂ LiGd _0.8 Eu _0.2 I ₆ : 14 mol %.

The scintillation glass-ceramic raw material components are P ₂ O ₅ : 40 mol%, B ₂ O ₃ : 25 mol%, BaF ₂ : 15 mol%, Gd ₂ O ₃ : 9 mol%, Cs ₂ LiGd _0.9 Tb _0.1 I ₆ : 11 mol% .

The preparation method of the _Cs2LiGdI6 glass _- ceramic doped with rare earth ions comprises the following steps:

(1) Melting of P ₂ O ₅ -B ₂ O ₃ -BaF ₂ -Gd ₂ O ₃ -Cs ₂ LiGd _(1-x) Ln _x I ₆ series glass: Cs ₂ LiGd _(1-x) Ln _x I6 The raw materials are mixed and sintered by CsI, LiI, GdI ₃ , LnI ₃ , and the analytically pure raw materials are weighed according to the raw material components, and NH ₄ HF ₂ and NH ₄ HI ₂ each accounting for 5% of the total weight of the raw materials are added, and the raw materials are mixed Evenly, then pour into a quartz crucible or corundum crucible to melt, the melting temperature is 1350-1450°C, keep warm for 1-2 hours, pour the glass melt into a cast iron mold, and then place it in a muffle furnace for annealing, at the glass transition temperature After the Tg temperature was kept for 1 hour, the temperature was lowered to 50°C at a rate of 10°C/hour, the power of the muffle furnace was turned off and the temperature was automatically lowered to room temperature, and the glass was taken out for microcrystallization heat treatment.

(2) Preparation of Cs ₂ LiGdI ₆ glass ceramics:

According to the glass thermal analysis (DTA) experimental data, the prepared glass is placed in a nitrogen precision annealing furnace, heat-treated at a temperature near its first crystallization peak for 4 to 6 hours, and then cooled at a rate of 5°C/hour to 50°C, turn off the power supply of the precision annealing furnace, automatically cool down to room temperature, and obtain transparent rare earth ion-doped Cs ₂ LiGdI ₆ glass-ceramics.

Compared with the prior art, the present invention has the advantages that: the glass-ceramic is composed of fluoroiodoxy compound, has good short _- wavelength transmission performance, has excellent scintillation performance of _Cs2LiGdI6 crystal matrix material and mechanical properties of oxide glass. The characteristics of strength, stability and easy processing overcome the shortcomings of Cs ₂ LiGdI ₆ single crystal, such as easy deliquescence, poor mechanical properties, and easy cleavage into flakes; it is proved by experiments that according to the formula and preparation method of the present invention, rare earth ion doping is precipitated Cs ₂ LiGdI ₆ crystal phase, the prepared rare earth ion doped Cs ₂ LiGdI ₆ glass-ceramics is transparent, deliquescence resistant, good mechanical properties, high short-wavelength blue-violet light transmittance, strong light output, fast Attenuation, good energy resolution and time resolution can greatly improve the efficiency of nuclear detectors. The preparation method of the crystallized glass is simple and the production cost is low.

Description of drawings

Fig. 1 is a transmission electron microscope image (TEM) of the sample after microcrystallization heat treatment in Example 1.

Fig. 2 is the fluorescence spectrum of Ce:Cs ₂ LiGdI ₆ glass ceramics excited by X-rays in Example 1.

Fig. 3 is the fluorescence spectrum of Eu:Cs ₂ LiGdI ₆ glass ceramics excited by X-rays in Example 2.

Fig. 4 is the fluorescence spectrum of Tb:Cs ₂ LiGdI ₆ glass ceramics excited by X-rays in Example 3.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Embodiment 1: Table 1 shows the glass formula and the first crystallization temperature value of Embodiment 1.

Table 1

The specific preparation process is as follows: the first step, Cs ₂ LiGd _0.95 Ce _0.05 I ₆ raw materials are mixed and sintered by CsI, LiI, GdI ₃ , CeI ₃ , weigh 50 grams of analytical pure raw materials according to the formula in Table 1, add 2.5 grams NH ₄ HF ₂ , 2.5 grams of NH ₄ HI ₂ , mix the raw materials evenly and pour them into a quartz crucible to melt, the melting temperature is 1350°C, keep warm for 2 hours, pour the glass melt into a cast iron mold, and then place it in a muffle furnace Carry out annealing, keep the temperature at the glass transition temperature Tg for 1 hour, then cool down to 50°C at a rate of 10°C/hour, turn off the power of the muffle furnace to automatically cool down to room temperature, and take out the glass; the second step, according to the thermal analysis of the glass (DTA ) experimental data, the first crystallization temperature was obtained at 680°C, and the prepared glass was placed in a nitrogen precision annealing furnace for heat treatment at 694°C for 6 hours, then cooled to 50°C at a rate of 5°C/hour, and the precision annealing furnace was closed The power supply is automatically cooled to room temperature, and a transparent Ce ³⁺ doped Cs ₂ LiGdI ₆ glass-ceramic sample is obtained.

The prepared Cs ₂ LiGdI ₆ glass-ceramic was tested by transmission electron microscope, and the transmission electron microscope picture of the glass obtained after microcrystallization treatment is shown in Figure 1. The results are as follows: the glass matrix and the precipitated nano-crystallites in the photo appear relatively It is clear that the black spots distributed in the glass matrix are microcrystalline particles. The X-ray diffraction test shows that the crystal phase is Cs ₂ LiGdI ₆ phase, so the obtained material is glass-ceramic of Cs ₂ LiGdI ₆ crystallization phase. The fluorescence spectrum of Ce ³⁺ ion-doped Cs ₂ LiGdI ₆ glass ceramics excited by X-rays is shown in Figure 2, and the fluorescence peak intensity is relatively large. The optical output of Ce ³⁺ ion Cs ₂ LiGdI ₆ glass ceramics is 32000ph/MeV, and the decay time is 75ns.

Embodiment 2: Table 2 shows the glass formula and the first crystallization temperature value of Embodiment 2.

Table 2

The specific preparation process is as follows: in the first step, Cs ₂ LiGd _0.8 Eu _0.2 I ₆ raw materials are mixed and sintered by CsI, LiI, GdI ₃ , EuI ₃ , weigh 50 grams of analytical pure raw materials according to the formula in Table 2, add 2.5 grams NH ₄ HF ₂ , 2.5 grams of NH ₄ HI ₂ , mix the raw materials evenly and pour them into a corundum crucible for melting, the melting temperature is 1450°C, keep warm for 1 hour, pour the glass melt into a cast iron mold, and then place it in a muffle furnace Carry out annealing, keep the temperature at the glass transition temperature Tg for 1 hour, then cool down to 50°C at a rate of 10°C/hour, turn off the power of the muffle furnace to automatically cool down to room temperature, and take out the glass; the second step, according to the thermal analysis of the glass (DTA ) experimental data, the first crystallization temperature was obtained at 682°C, and the prepared glass was placed in a nitrogen precision annealing furnace for heat treatment at 695°C for 4 hours, then cooled to 50°C at a rate of 5°C/hour, and the precision annealing furnace was closed The power supply automatically cools down to room temperature, and a transparent Eu ³⁺ ion-doped Cs ₂ LiGdI ₆ glass-ceramic is obtained.

As for the spectral properties of the prepared Cs ₂ LiGdI ₆ glass-ceramics, the fluorescence spectrum of Eu ³⁺ ion-doped Cs ₂ LiGdI ₆ glass-ceramics excited by X-rays is shown in Figure 3, and the results show that Eu is produced after heat treatment: The luminous intensity of Cs ₂ LiGdI ₆ crystallites is significantly improved compared with the corresponding glass matrix, indicating that Eu:Cs ₂ LiGdI ₆ glass-ceramics has better luminous properties.

Embodiment 3: Table 3 shows the glass formula and the first crystallization temperature value of Embodiment 3.

Table 3 Table 1

The specific preparation process is as follows: the first step, Cs ₂ LiGd _0.9 Tb _0.1 I ₆ raw materials are mixed and sintered by CsI, LiI, GdI ₃ , TbI ₃ , weigh 50 grams of analytical pure raw materials according to the formula in Table 3, add 2.5 grams NH ₄ HF ₂ , 2.5 grams of NH ₄ HI ₂ , mix the raw materials evenly and pour them into a quartz crucible to melt, the melting temperature is 1400°C, keep warm for 1.5 hours, pour the glass melt into a cast iron mold, and then place it in a muffle furnace Carry out annealing, keep at the glass transition temperature Tg for 1 hour, then cool down to 50°C at a rate of 10°C/hour, turn off the power of the muffle furnace to automatically cool down to room temperature, and take out the glass. In the second step, according to the glass thermal analysis (DTA) experimental data, the first crystallization temperature is 689°C, and the prepared glass is placed in a nitrogen precision annealing furnace at 720°C for 5 hours, and then at 5°C/hour The temperature was lowered to 50°C at a certain speed, and the precision annealing furnace was turned off to automatically cool down to room temperature to obtain transparent Tb ³⁺ ion-doped Cs ₂ LiGdI ₆ glass-ceramics.

Test the spectral properties of the prepared Cs ₂ LiGdI ₆ glass-ceramics. The fluorescence spectrum of the Tb ³⁺ ion-doped Cs ₂ LiGdI ₆ glass-ceramics excited by X-rays is shown in Figure 4. The results show that Cs ₂ Compared with the corresponding glass matrix, the luminous intensity of LiGdI ₆ crystallites has been significantly improved, indicating that the luminescent properties of Tb:Cs ₂ LiGdI ₆ glass-ceramics are better; the rare earth ion-doped Cs ₂ LiGdI ₆ Glass-ceramic is transparent and has excellent physical and chemical properties.

Example 4

It is basically the same as Example 1, except that the raw material components are different: P ₂ O ₅ : 30 mol%, B ₂ O ₃ : 30 mol%, BaF ₂ : 20 mol%, Gd ₂ O ₃ : 5 mol%, Cs ₂ LiGd _0.95 Pr _0.05 I ₆ : 15 mol%.

Example 5

It is basically the same as Example 1, except that the raw material components are different: P ₂ O ₅ : 30mol%, B ₂ O ₃ : 30mol%, BaF ₂ : 20mol%, Gd2O ₃ : 5mol%, Cs ₂ LiGd _0.95 Nd _0.05 I ₆ : 15 mol%.

Examples 4 and 5 can also obtain better rare earth ion-doped Cs ₂ LiGdI ₆ glass-ceramics, and the specific spectra of the scintillation glass-ceramics will not be provided one by one.

Claims (5)

1. a rare earth ion doped Cs ₂liGdI ₆devitrified glass, its Mole percent consists of:

P ₂O ₅：30-40mol％B ₂O ₃：25-30mol％BaF ₂：15-20mol％

Gd ₂o ₃: 5-9mol%Cs ₂liGd _(1-x)ln _xi ₆: 11-15mol%, in formula, x=0.05-0.2, Ln are Ce ³⁺, Eu ³⁺, Tb ³⁺, Pr ³⁺and Nd ³⁺in a kind of rare earth ion.

2. rare earth ion doped Cs according to claim 1 ₂liGdI ₆devitrified glass, is characterized in that this devitrified glass material component is: P ₂o ₅: 30mol%, B ₂o ₃: 30mol%, BaF ₂: 20mol%, Gd ₂o ₃: 5mol%, Cs ₂liGd _0.95ce _0.05i ₆: 15mol%.

3. rare earth ion doped Cs according to claim 1 ₂liGdI ₆devitrified glass, is characterized in that this devitrified glass material component is: P ₂o ₅: 35mol%, B ₂o ₃: 28mol%, BaF ₂: 17mol%, Gd ₂o ₃: 6mol%, Cs ₂liGd _0.8eu _0.2i ₆: 14mol%.

4. rare earth ion doped Cs according to claim 1 ₂liGdI ₆devitrified glass, is characterized in that this devitrified glass material component is: P ₂o ₅: 40mol%, B ₂o ₃: 25mol%, BaF ₂: 15mol%, Gd ₂o ₃: 9mol%, Cs ₂liGd _0.9tb _0.1i ₆: 11mol%.

5. rare earth ion doped Cs according to claim 1 ₂liGdI ₆the preparation method of devitrified glass, is characterized in that comprising following concrete steps:

(1) P ₂o ₅-B ₂o ₃-BaF ₂-Gd ₂o ₃-Cs ₂liGd _(1-x)ln _xi ₆be founding of glass: Cs ₂liGd _(1-x)ln _xi ₆raw material is by CsI, LiI, GdI ₃, LnI ₃mixed sintering forms, and takes analytically pure each raw material by the material component of devitrified glass, adds the NH accounting for devitrified glass raw material gross weight 5% ₄hF ₂, add the NH accounting for devitrified glass raw material gross weight 5% ₄hI ₂raw material is mixed, then pours in quartz crucible or corundum crucible and melt, temperature of fusion 1350-1450 DEG C, insulation 1-2 hour, glass melt is poured in pig mold, be then placed in retort furnace and anneal, in glass transformation temperature Tg temperature after 1 hour, 50 DEG C are cooled to the speed of 10 DEG C/h, close retort furnace power supply and be automatically cooled to room temperature, take out glass, for micritization thermal treatment;

(2) Cs ₂liGdI ₆the preparation of devitrified glass: according to the thermal analysis experiment data of glass, obtained glass is placed in nitrogen fine annealing stove, heat-treated 4 ~ 6 hours near its first crystallization peak, and then be cooled to 50 DEG C with the speed of 5 DEG C/h, close fine annealing stove power supply, automatically be cooled to room temperature, obtain transparent rare earth ion doped Cs ₂liGdI ₆devitrified glass.