Magnetic memory device and magnetic memory

1. A magnetic memory device comprising:

a first magnetic section including an extending portion extending in a first direction, the extending portion having a first interface extending along the first direction and a second interface extending along the first direction on opposite side from the first interface, the extending portion including a plurality of magnetic domains arranged along the first direction, magnetization easy axis of the extending portion being directed along a second direction crossing the first direction, and the extending portion including:

a first region provided between the first interface and the second interface and containing at least one first element selected from a first group consisting of gadolinium, terbium, dysprosium, neodymium, and holmium; and

a second region provided between the first region and the first interface and containing at least one second element selected from a second group consisting of iron, cobalt, nickel, boron, silicon, and phosphorus, concentration of the first element in the second region being lower than concentration of the first element in the first region;

a read section configured to read magnetization direction of one of the magnetic domain in the extending portion; and

a write section configured to control the magnetization direction of one of the magnetic domain in the extending portion.

2. The device according to claim 1 , wherein

the first region contains the second element, and

concentration of the second element in the first region is higher than the concentration of the first element in the second region.

3. The device according to claim 1 , wherein

the second region contains the first element, and

concentration of the second element in the second region is higher than the concentration of the first element in the second region.

4. The device according to claim 1 , wherein the second element includes at least one of iron, cobalt, and nickel, and at least one of boron, silicon, and phosphorus.

5. The device according to claim 1 , wherein

the first magnetic section further includes a third region provided between the first region and the second interface,

the third region contains the first element and the second element, and

concentration of the first element in the third region is lower than the concentration of the first element in the first region.

6. The device according to claim 5 , wherein at least one of the second region and the third region contains at least one third element selected from a third group consisting of tantalum, tungsten, iridium, platinum, palladium, copper, aluminum, silver, gold, carbon, magnesium, and hafnium.

7. The device according to claim 1 , further comprising:

a first layer; and

a second layer,

wherein the extending portion is provided between the first layer and the second layer, and

at least one of the first layer and the second layer contains at least one of tantalum, tungsten, iridium, platinum, palladium, copper, aluminum, silver, gold, carbon, silicon, magnesium, and hafnium.

8. The device according to claim 1 , further comprising:

a first layer; and

a second layer,

wherein the extending portion is provided between the first layer and the second layer, and

at least one of the first layer and the second layer contains at least one of tantalum nitride, tungsten nitride, silicon nitride, aluminum nitride, magnesium oxide, aluminum oxide, silicon oxide, and hafnium oxide.

9. The device according to claim 1 , wherein outer edge of a cross section of the extending portion in a plane crossing the first direction is a rectangle, trapezoid, circle, ellipse, or polygon.

10. The device according to claim 1 , further comprising:

a first layer; and

a second layer extending in the first direction,

wherein the extending portion is provided around the second layer in the second direction, and

the first layer is provided around the extending portion in the second direction.

11. The device according to claim 10 , wherein outer edge of a cross section of the extending portion in a plane crossing the first direction is a circle, ellipse, or polygon.

12. The device according to claim 1 , wherein

the extending portion includes a plurality of first portions and a plurality of second portions arranged alternately along the first direction, and

distance between one end in the second direction of the first portion and the other end in the second direction of the first portion is larger than distance between one end in the second direction of the second portion and the other end in the second direction of the second portion.

13. The device according to claim 1 , further comprising:

a first electrode connected to the first magnetic section; and

a second electrode connected to a portion of the first magnetic section, the portion being different from a portion connected with the first electrode.

14. A magnetic memory comprising:

a plurality of the magnetic memory devices according to claim 13 ;

a first transistor including a first gate, a first terminal connected to the first electrode of one of the plurality of magnetic memory devices, and a second terminal;

a first word line connected to the first gate; and

a first bit line connected to the second electrode of the one of the plurality of magnetic memory devices.

15. A magnetic memory device comprising:

a first magnetic section including an extending portion extending in a first direction, the extending portion having a first interface extending along the first direction and a second interface extending along the first direction on opposite side from the first interface, the extending portion including a plurality of magnetic domains arranged along the first direction, magnetization easy axis of the extending portion being directed along a second direction crossing the first direction, and the extending portion including:

a first region provided between the first interface and the second interface and containing at least one first element selected from a first group consisting of gadolinium, terbium, dysprosium, neodymium, and holmium; and

a second region provided between the first region and the first interface and containing at least one second element selected from a second group consisting of iron, cobalt, nickel, boron, silicon, and phosphorus, concentration of the first element in the second region being lower than concentration of the first element in the first region;

a second magnetic section; and

a nonmagnetic section provided between the first magnetic section and the second magnetic section.