JPH01296484A - Brochure memory element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solid-state magnetic memory, and particularly to a Bloch line memory element suitable for realizing a large-capacity file memory.

[Conventional technology]

Conventionally, as a method for reading out stored information in a Bloch line memory, the method described in Japanese Patent Laid-Open No. 1.01092/1982 is well known. This method will be explained with reference to FIG. That is, when a Bloch line exists in a domain wall of a striped magnetic domain, the direction of magnetization in the domain wall is reversed by 180 degrees with the Bloch line as a boundary. Due to such a change in the magnetization structure, when the Bloch line 11 is located at the end of the striped magnetic domain 4 as shown in FIG. 5(a), the direction of magnetization within the domain walls on both sides is parallel, and as shown in FIG. 5(C). As shown, when a Bloch line does not exist at the end of the striped magnetic domain 4, the directions of magnetization within the domain walls on both sides become antiparallel, and there is a difference in the ease of cutting the striped magnetic domain end between the two.

That is, there is a Bloch line 1 at the end of the striped magnetic domain 4.
1 exists (FIG. 5(a)), the bubble magnetic domain 9 is cut from the edge of the stripe magnetic domain 4 by passing a predetermined current through the magnetic domain cutting core 10 provided at the edge of the stripe magnetic domain.
However, if a Bloch line does not exist at the end of the striped magnetic domain 4 (FIG. 5(C)), no bubble domain is cut out even if current is passed through the magnetic domain cutting conductor 10. The presence of Bloch lines can be read by transferring the bubble magnetic domain 5 cut out in FIG. 5(b) and converting it into an electrical signal.

Another readout method is the rough method, which uses a meandering conductor as a conductor for cutting striped magnetic domains.
It is mentioned in .

This method will be explained with reference to FIG. This method is.

A meandering conductor 13 is provided at the second part of the striped magnetic domain 4 as a conductor for cutting the striped magnetic domain, and the striped magnetic domain is cut at the openings of the eight recesses.

[Problem to be solved by the invention]

Among the conventional techniques mentioned above, the method using hairpin-like thick bodies has the problem that in actual devices in which many striped magnetic domains are arranged in parallel, the length of the conductor becomes very long, which increases the resistance of the conductor and lowers the withstand voltage. Furthermore, due to phosphorography, if a short circuit occurs between the conductors at even one place, a problem arises in that the entire chip cannot be read.

On the other hand, the method of using a meandering conductor has the advantage that the resistance is lower /h and the withstand voltage is higher because it is a single conductor, but since the magnetic domain is cut at the recess of the conductor, the dimensions of the opening of the recess are smaller than the magnetic domain. This requires more than the width, and the period in which the striped magnetic domains are lined up has to be doubled compared to the method using hairpin-shaped conductors, so there is a problem that the storage density is halved.

Furthermore, the above two methods require a conductor to insert the bubble magnetic domain cut out by the read operation into the measure line, making the read operation complicated.

The purpose of the present invention is to make the period in which striped magnetic domains are arranged the same as when using a hairpin-shaped core, and to use a meandering conductor as a striped magnetic domain cutting conductor to increase the withstand voltage of the conductor.
The object of this invention is to simplify the operation of inserting the bubble magnetic domain cut out by the read operation into the major line.

[Means to solve the problem]

The above object is achieved by extending the striped magnetic domain in a direction perpendicular to the longitudinal direction, providing a conductor for cutting the striped magnetic domain in the part extending in the orthogonal direction, and cutting the striped magnetic domain on the major line.

[Function] When the striped magnetic domain is expanded or contracted, if the shape of the end of the long and narrow pattern that acts as a guardrail is made into an asymmetrical shape as shown in Figure 2, the shape will be connected to the major line (transfer path of the bubble magnetic domain) outside the guardrail. A low bias magnetic field can be generated periodically. Furthermore, by providing a meandering conductor in the measure line and passing a current through it, the bias magnetic field can be periodically lowered. When the striped magnetic domains are extended in this state, the striped magnetic domains extend in the longitudinal direction between the guardrails, but at the major lines outside the guardrails, they are bent and extended in a direction perpendicular to the longitudinal direction. Bending the striped magnetic domains can also be achieved by providing a convex portion inside the pattern that surrounds the functional area and prevents the intrusion of magnetic domains from the outside.

By providing a meandering conductor having four parts perpendicular to a part of the striped magnetic domain bent in a direction perpendicular to the longitudinal direction of the striped magnetic domain, the dimension of the opening of the recess can be narrowed, and the period in which the striped magnetic domains are lined up can be adjusted to Stripe magnetic domains can be cut by the meandering conductor while the conductor remains the same as when used, and the withstand voltage of the conductor for cutting stripe magnetic domains can be increased. Furthermore, by extending the striped magnetic domain on the major line in a direction perpendicular to the longitudinal direction and cutting the magnetic domain at that part, it is possible to simplify the operation of inserting the bubble magnetic domain cut out by the read operation into the major line.

〔Example〕

Example 1゜ A first embodiment of the present invention will be described below with reference to FIG.

In the figure, 1 is a pattern for fixing the striped magnetic domain, 2 is a pattern that serves as a guardrail when expanding and contracting the striped magnetic domain, and 3 is a pattern that serves to prevent unnecessary magnetic domains from entering the functional part from the outside. . The shaded area A is the transfer path (major line) of the bubble magnetic domain after converting the presence or absence of a Bloch line pair into the presence or absence of a bubble domain. Bloch line pairs 101, which are information carriers, are usually stored in striped magnetic domains in a contracted state as shown in FIG. 1(a).

By lowering the bias magnetic field when writing and reading Bloch lines, stripe magnetic domains are extended along the guardrail 2, but if the shape of the end of the guardrail 2 is made asymmetrical as shown in FIG. 2(a), For example, if the guardrail 2 is made of a magnetic material and magnetized in the opposite direction to the stripe magnetic domain, the magnetic field created by the magnetic poles at the ends 201 and 202 on the major line 2 is wider in the area 201, so The bias magnetic field in the shaded area B in Figure 1 is lower than the surrounding area, so when the stripe magnetic domain is extended, the guardrail 2
In the part, the striped magnetic domain extends in the longitudinal direction,
The guardrail 2 extends curved in a direction perpendicular to the longitudinal direction at the outer diagonally shaded portion A (FIG. 1(b)). The striped magnetic domain is cut by a meandering conductor 5 having a concave portion orthogonal to a portion of the striped magnetic domain extending in a direction perpendicular to the longitudinal direction of the striped magnetic domain.

According to this embodiment, a meandering conductor having a concave portion perpendicular to the striped magnetic domains can be provided as a striped magnetic domain cutting conductor, and since the concave portion is perpendicular to the striped magnetic domains, the opening portion 6 of the concave portion can be narrowed. Compared to the case of a meandering conductor as shown in Fig. 6 (the conductor for stripe magnetic domain cutting must be provided in the shaded area (c) in Fig. 1),
The period in which striped magnetic domains are lined up can be halved. Furthermore, since it is a straight conductor, the withstand voltage is higher than that in the case of using a hairpin-shaped conductor as described in JP-A-58-101092. Furthermore, since striped magnetic domains are cut on the measure line, there is no need to insert the cut out bubble magnetic domain into the measure line.

(This embodiment can be applied not only to read operations but also to write operations.) Embodiment 2 A second embodiment will be explained with reference to FIG. A meandering conductor 7 for bending the magnetic domain is provided in the shaded area A in the figure in addition to the meandering conductor for reading shown in FIG. 1, and a current IC is passed through it. Then, the bias magnetic field in the shaded area B becomes lower due to the magnetic field generated thereby. When the striped magnetic domain is extended in this state, the striped magnetic domain extends in a direction perpendicular to its longitudinal direction at the hatched portion A. Thereafter, as in Example 1, the striped magnetic domains are cut by the reading meandering conductor (path shown).

Embodiment 3 A third embodiment will be explained with reference to FIG. Convex part 8 in pattern 3 to prevent unnecessary magnetic domains from entering the functional part 3 in the figure.
will be established. In this case, especially when the convex portion is provided below the center line of the two guardrails as shown in the figure, when the stripe magnetic domain is extended, the stripe magnetic domain receives a repulsive force from the convex portion 8 and moves upward, that is, the stripe magnetic domain It bends in a direction perpendicular to the longitudinal direction, and stops when it stretches a little due to the repulsive force from the adjacent convex part. Thereafter, stripe magnetic domains are cut in the same manner as in Example 1.

〔Effect of the invention〕

According to the present invention, a conductor with high withstand voltage can be provided as a conductor for cutting striped magnetic domains without increasing the period in which the striped magnetic domains are arranged, so that the life of the conductor can be extended and the storage density can be increased. Furthermore, striped magnetic domains can be cut on the measure line, and there is no need to put the cut out bubble magnetic domains on the measure line, so the reliability of the read operation can be improved.

[Brief explanation of the drawing]

1, 3, and 4 are plan views of the storage end of the Bloch line memory element for explaining the present invention in detail; FIG. 2 is an enlarged plan view of the guardrail 2 in FIG. 1; FIG. 5 is a diagram explaining the principle of the Bloch line reading method, and FIG. 6 is a plan view showing the positional relationship between the striped magnetic domains and the meandering floating body when a meandering conductor is used as a Bloch line readout conductor. 1... Striped magnetic domain fixing pattern, 2, 3... Guardrail, 4... Striped magnetic domain, 5... Meandering hot body for cutting magnetic domains, 7... Meandering floating body, 9... Bubble magnetic domain, 1
0...Hairpin shaped sensor, 1 Tobloch line, 12...
Domain wall, 13...Meandering conductor, A...Bubble magnetic domain transfer path, B...Writing and reading function unit, 10.1...
Blochline Vs.

Claims (1)

[Claims] 1. A Bloch line memory in which information carriers are Bloch line pairs existing in striped magnetic domains arranged in parallel in a ferromagnetic material whose axis of easy magnetization is perpendicular to the film surface. In writing and reading information in an element, it is recommended to extend at least the stripe magnetic domain ends in a direction perpendicular to the longitudinal direction thereof, provide a conductor in the part extending in the perpendicular direction, and write and read information in that part. Features a Bloch line memory element. 2. Claim 1 is characterized in that when expanding and contracting the striped magnetic domain, the shape of the end of the elongated pattern that serves as a guardrail is made asymmetrical so that the striped magnetic domain is extended in a direction perpendicular to its longitudinal direction. Bloch line memory element. 3. In claim 1, a conductor is provided in the transfer path of the bubble magnetic domain, and a magnetic field generated by passing a current through the conductor is used to extend the striped magnetic domain in a direction perpendicular to its longitudinal direction. A Bloch line memory element characterized by: 4. In claim 1, a convex portion is provided inside the pattern surrounding the functional part of the Bloch line memory to prevent the intrusion of magnetic domains from the outside, and the striped magnetic domains are extended in a direction perpendicular to the longitudinal direction of the pattern. A Bloch line memory element characterized by: 5. In claim 3, a striped magnetic domain is extended in a direction perpendicular to the longitudinal direction of the bubble magnetic domain in a transfer path, the magnetic domain is cut at that part, and the cut out bubble magnetic domain is transferred to the transfer path. A Bloch line memory device characterized by a simple loading operation. 6. In claim 2, the asymmetry of the guardrail is achieved by forming a mask pattern on the ferromagnetic material, creating crystal distortion by ion implantation, and selectively chemically etching the ferromagnetic material to form a groove. A Bloch line memory element characterized in that it forms and generates a guardrail.