SU912064A3 - Channel for movement of cylindrical magnetic domains - Google Patents

Description

The invention relates to automation and computer technology and can be used in the construction of storage devices on cylindrical magnetic domains (CMD).

A known channel for promoting CMD containing a magnetically uniaxial film with CMD, on which parallel conductive 'buses are located [1).

The disadvantage of this channel is the complexity of the control electronics and the limited recording density of information.

Closest to the proposed channel is for the promotion of CMD, which contains ferromagnetic elements located on a magnetically uniaxial film with CMD. ed

CMDs are cylindrical magnetization regions propagating in a magnetically uniaxial film under the influence of local magnetic fields. In the well-known channel for the promotion of CMD, the source of such local magnetic fields is the T- and Ι-shaped ferromagnetic elements, periodically magnetized by an external magnetic control field rotating in the plane of a magnetically uniaxial film [2]. ed

The disadvantages of this channel for the promotion of CMD are their non-technological properties with a decrease in the diameter of the CMD, which leads to. reduced yield of devices, and low reliability (reducing the area of stable operation), especially with an increase in the operating frequency.

The purpose of the invention is to increase the reliability of the channel for the promotion of CMD.

This goal is achieved by the fact that in it the ferromagnetic elements are made with convex external and concave internal sides adjacent to the bases of the ferromagnetic elements. ''

In this case, the ferromagnetic elements can be asymmetric with respect to the vertical axis, the outer side of the ferromagnetic elements is made semicircular or V-shaped, the width of the ferromagnetic elements adjacent to the base of the jumpers is less than their length.

In FIG. 1-8 depict ferromagnetic elements of various shapes; in FIG. 9 areas of sustainable operation of the proposed and well-known. Channels for the promotion of CMD.

The channel for advancing the CMD contains ferromagnetic elements 1 located on a magnetically uniaxial film 2 with a CMD 3. The outer side of the ferromagnetic elements ί can be semicircular (Fig. 1-7) or V-shaped (Fig. 8) in shape. Ferromagnetic elements 1 can be symmetric (Fig. 6) and asymmetric (Figs. 1-5, 7, and 8) with respect to the vertical axis.

The sequence of asymmetric ferromagnetic elements 1 in the channel determines the direction of propagation of the CMD. The use of the proposed ferromagnetic elements allows for the possibility of defects and a change in the gap 4 (Fig. 1) between the elements and provides for a smaller number of elements per channel period for the promotion of CMD.

The device operates as follows.

Let _for determination, the vector of the control field H \ rotates counterclockwise and occupies the positions A, B, C, and D in sequence. The corresponding positions of the extended CMD on element 1 are shown in FIGS. 2-5. The transition of the CMD from one element 1 to the next occurs under the action of an elongated attracting pole arising on this element (Fig. 2). The shape of the CMD (the degree of its extension) depends on the position of the domain under element 1 and the magnitude of the displacement field N _cm . The relationship between elements 1 in the proposed channel is chosen so as to ensure the nucleation of the pole to which the CMD moves in each case, when it moves from one element to the nearest, until the pole is weakened and neutralized at the location previously occupied by the CMD. The pole on the receiving element has an elongated shape, and as the CMD moves between the elements, its magnetic charge increases more and more. The presence of an elongated pole in this case leads to an increase in the stability of the CMD transition.

In FIG. 7 shows a ferromagnetic element in the form of a half-disk, beveled in the direction of the vertical axis. In such a channel, the transition of the CMD from one element 1 to the neighboring one occurs somewhat earlier than in a channel with ordinary half-disk elements.

In FIG. Figure 9 shows typical areas of sustainable operation (ESD) of the proposed and known channels for promoting CMD on T- and 1-shaped elements in coordinates

-N. As follows from FIG. 9, the use of the proposed channel for the promotion of CMD allows you to expand both the lower and upper boundaries of the ESD channel. In addition, channel 5 can operate with smaller control fields H.

Thus, the use of the proposed channel for the promotion of CMD allows expanding the ESD, makes the channel operation less sensitive to the presence of defects and the size of the gap between the elements, which, in turn, improves the reliability of the channel for the promotion of the CMD.

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Claims (2)

The channel for promotion of CMD contains ferromagnetic elements 1 located on a magnetically uniaxial film 2 with CMD 3. The side of the ferromagnetic elements 1 can be semicircular (Fig. 1-7) or Y-shaped (Fig. 8). Ferromagnetic elements 1 can be symmetrical (Fig. 6) and asymmetrical (Fig. 1-5, 7 and 8) about the vertical axis. The sequence of asymmetric ferromagnetic elements 1 in the channel determines the direction of propagation of the CMD. The use of the proposed ferromagnetic elements allows for the presence of defects and a change in the gap 4 (Fig. 1) between the elements and provides for a smaller number of elements per channel period for the promotion of CMD. The device works as follows. Let e; 1 of the definition of the vector field control H rotate counterclockwise and take consecutive positions A, B, C and D. The corresponding positions of the expanded CMD on element 1 are shown in FIG. 2-5. The transition of the CMD from one element to the next occurs under the action of an elongated attracting pole arising on this element (Fig. 2). The form of CMD (the degree of its stretching) depends on the position of the domain under element 1 and the size of the displacement field. The relationship between elements 1 in the proposed channel is chosen such as to ensure the birth of the pole to which the CMD moves in each case, when it moves from one element to the closest one, before weakening and neutralizing the pole in the location previously occupied by the CMD. The pole on the receiving element has an elongated shape, and when the CMD moves between the elements, its magnetic charge increases more and more. The presence of an elongated pole in this case leads to a decrease in the stability of the CMD transition. FIG. 7 shows a ferromagnetic element in the form of a half-disk, beveled along the direction of the vertical axis. In such a channel, the transition of a CMD from one element 1 to an adjacent one occurs somewhat earlier than in a channel with ordinary semi-disk elements. FIG. Figure 9 shows typical areas of stable operation (ESD) of the proposed and known channels for advancing CMD on T- and 1-shaped elements in coordinates Ho-H, 1 cw follows from FIG. 9, the use of the proposed channel to advance the CMD allows the expansion of both the lower and upper limits of the ESD channel. In addition, the channel can operate with smaller control fields H. Thus, the use of the proposed channel to advance the CMD allows to expand ESD, makes the channel less sensitive to the presence of defects and the size of the gap between the elements, which, in turn, improves the reliability of the channel to promote the CMD. Claim 1. Channel for promotion of cylindrical magnetic domains containing ferromagnetic elements located on a magnetically uniaxial film with cylindrical magnetic domains, characterized in that, in order to increase the reliability of the channel for promotion of cylindrical magnetic domains, ferromagnetic elements are made with convex outer and concave inner sides adjacent to the base of ferromagnetic elements. 2. A channel for advancing the cylindrical magnetic domains according to claim I, in that the ferromagnetic elements are asymmetrical about the vertical axis. 3. Channel to promote cylindrical ;; The magnetic domains according to claim 2, which also means that the outer side of the ferromagnetic elements is semicircular. 4. A channel for advancing the cylindrical magnetic domains according to claim 2, in that the outer side of the ferromagnetic elements is V-shaped. 5. Channel for promotion of cylindrical magnetic domains on PP. 3 and 4, which is due to the fact that the width of the ferromagnetic elements adjacent to the base of the bridges is less than their length. Sources of information taken into account in the examination 1.IEEE Trans. Magn ,, V. MAG - 5, p, 544, 1969. 2. US Patent No. 3534347, cl. G 11 C 11/14, 1970 (prototype).