Spin current-electric current conversion structure, thermoelectric conversion element using the same, and method for making the same

Patent metadata

Field	Value
Publication number	US-2018033940-A1
Application number	US-201615549910-A
Country	US
Kind code	A1
Filing date	Feb 17, 2016
Priority date	Feb 26, 2015
Publication date	Feb 1, 2018
Grant date	—

Abstract

A spin current-electric current conversion structure using a material containing 5d-transition metal has low efficiency of spin current-electric current conversion; therefore, a spin current-electric current conversion structure according to an exemplary aspect of the present invention includes a 4d-transition metal oxide structure consisting primarily of an oxide containing a 4d-transition-metal element; a spin current input-output structure configured to allow a spin current to flow into and out in a direction perpendicular to a plane of the 4d-transition metal oxide structure; and an electric current input-output structure configured to allow an electric current to flow into and out, the electric current conducting in an in-plane direction of the 4d-transition metal oxide structure.

First claim

1 . A spin current-electric current conversion structure, comprising:
a 4d-transition metal oxide structure consisting primarily of an oxide containing a 4d-transition-metal element; a spin current input-output structure configured to allow a spin current to flow into and out in a direction perpendicular to a plane of the 4d-transition metal oxide structure; and an electric current input-output structure configured to allow an electric current to flow into and out, the electric current conducting in an in-plane direction of the 4d-transition metal oxide structure.

2 . The spin current-electric current conversion structure according to claim 1 ,
wherein a valence of the 4d-transition metal in the oxide containing the 4d-transition-metal element is determined so that a spin Hall angle of the oxide containing the 4d-transition-metal element may be maximized.

3 . The spin current-electric current conversion structure according to claim 1 ,
wherein the oxide containing the 4d-transition-metal element includes at least one of ruthenium oxide, rhodium oxide, and niobium oxide.

4 . The spin current-electric current conversion structure according to claim 1 ,
wherein a thickness of the oxide containing the 4d-transition-metal element in a direction perpendicular to a plane of the oxide is not less than two nanometers and not more than thirty nanometers.

5 . A thermoelectric conversion element, comprising:
a magnetic material layer containing a magnetic material exhibiting spin Seebeck effect; and an electromotive material connected to the magnetic material layer so that a spin current can flow into and out, and configured to generate electromotive force due to inverse spin Hall effect, wherein the electromotive material includes a spin current-electric current conversion structure, and the spin current-electric current conversion structure includes a 4d-transition metal oxide structure consisting primarily of an oxide containing a 4d-transition-metal element, a spin current input-output structure configured to allow a spin current to flow into and out in a direction perpendicular to a plane of the 4d-transition metal oxide structure, and an electric current input-output structure configured to allow an electric current to flow into and out, the electric current conducting in an in-plane direction of the 4d-transition metal oxide structure.

6 . The thermoelectric conversion element according to claim 5 , further comprising
a substrate on which the magnetic material layer is mounted, and two electrode sections electrically connected to the electromotive material and disposed apart from each other.

7 . A memory element, comprising:
a magnetic free layer; a barrier layer connected to the magnetic free layer; a magnetic fixed layer configured to form a tunnel junction with the magnetic free layer through the barrier layer; and a conductive layer disposed so that a spin current may arise due to spin Hall effect, and so that the spin current may flow into the magnetic free layer, wherein the conductive layer includes the spin current-electric current conversion structure according to claim 1 .

8 . A method for making a thermoelectric conversion element, comprising:
stacking, on a substrate, a magnetic material layer containing a magnetic material exhibiting spin Seebeck effect; stacking, on the magnetic material layer, an electromotive material connected to the magnetic material layer so that a spin current can flow into and out, and configured to generate electromotive force due to inverse spin Hall effect; and forming two electrode sections apart from each other, each of which is electrically connected to the electromotive material, wherein the stacking of the electromotive material includes forming the electromotive material in such a way as to include a spin current-electric current conversion structure, and the spin current-electric current conversion structure includes a 4d-transition metal oxide structure consisting primarily of an oxide containing a 4d-transition-metal element, a spin current input-output structure configured to allow a spin current to flow into and out in a direction perpendicular to a plane of the 4d-transition metal oxide structure, and an electric current input-output structure configured to allow an electric current to flow into and out, the electric current conducting in an in-plane direction of the 4d-transition metal oxide structure.

9 . The method for making the thermoelectric conversion element according to claim 8 , further comprising
performing thermal treatment, after forming the electromotive material including the spin current-electric current conversion structure, so that a valence of the 4d-transition metal in the oxide containing the 4d-transition-metal element may have a value by which to maximize a spin Hall angle of the oxide containing the 4d-transition-metal element.

10 . The method for making the thermoelectric conversion element according to claim 8 ,
wherein the forming the electromotive material including the spin current-electric current conversion structure is performed by using a coating-based formation method.

11 . The spin current-electric current conversion structure according to claim 2 ,
wherein the oxide containing the 4d-transition-metal element includes at least one of ruthenium oxide, rhodium oxide, and niobium oxide.

12 . The spin current-electric current conversion structure according to claim 2 ,
wherein a thickness of the oxide containing the 4d-transition-metal element in a direction perpendicular to a plane of the oxide is not less than two nanometers and not more than thirty nanometers.

13 . The spin current-electric current conversion structure according to claim 3 ,
wherein a thickness of the oxide containing the 4d-transition-metal element in a direction perpendicular to a plane of the oxide is not less than two nanometers and not more than thirty nanometers.

14 . The thermoelectric conversion element according to claim 5 ,
wherein a valence of the 4d-transition metal in the oxide containing the 4d-transition-metal element is determined so that a spin Hall angle of the oxide containing the 4d-transition-metal element may be maximized.

15 . The thermoelectric conversion element according to claim 5 ,
wherein the oxide containing the 4d-transition-metal element includes at least one of ruthenium oxide, rhodium oxide, and niobium oxide.

16 . The thermoelectric conversion element according to claim 14 ,
wherein the oxide containing the 4d-transition-metal element includes at least one of ruthenium oxide, rhodium oxide, and niobium oxide.

17 . The thermoelectric conversion element according to claim 5 ,
wherein a thickness of the oxide containing the 4d-transition-metal element in a direction perpendicular to a plane of the oxide is not less than two nanometers and not more than thirty nanometers.

18 . The thermoelectric conversion element according to claim 14 ,
wherein a thickness of the oxide containing the 4d-transition-metal element in a direction perpendicular to a plane of the oxide is not less than two nanometers and not more than thirty nanometers.

19 . The thermoelectric conversion element according to claim 15 ,
wherein a thickness of the oxide containing the 4d-transition-metal element in a direction perpendicular to a plane of the oxide is not less than two nanometers and not more than thirty nanometers.

20 . The method for making the thermoelectric conversion el

Assignees

• Nec Corp

Inventors

• Kirihara Akihiro
• Ishida Masahiko
• Ihara Kazuki
• Iwasaki Yuma
• Someya Hiroko

Classifications

• H01L35/28

  Electricity · mapped topic

• H01L35/34

  Electricity · mapped topic

• G11C11/161

  details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell · CPC title

• H01L43/04

  Electricity · mapped topic

• H01L43/08

  Electricity · mapped topic