Spin Seebeck Effect New Paradigm for energy harvesting Sadamichi - - PowerPoint PPT Presentation

▶

Oct 23, 2023 203 likes •395 views

JST Japan-Spain Meeting (March 5, 2013) Spin Seebeck Effect New Paradigm for energy harvesting Sadamichi Maekawa Advanced Science Research Center, Japan Atomic science Agency, Tokai, Japan JST Japan-Spain Collaboration : Development in Spin

SLIDE 1

Spin Seebeck Effect

JST Japan-Spain Collaboration : “Development in Spin Seebeck Devices” Maekawa goup (JAEA), Saitoh group (Tohoku University), Ibarra group (University of Zaragoza).

JST Japan-Spain Meeting (March 5, 2013)

Sadamichi Maekawa

Advanced Science Research Center, Japan Atomic science Agency, Tokai, Japan

New Paradigm for energy harvesting

SLIDE 2

JST Japan-Spain Collaboration: “Development in Spin Seebeck Devices” Japanese Team: Maekawa Group (ASRC, JAEA, Tokai): Theory of spin Seebeck effect, Saitoh Group (IMR, Tohoku University, Sendai): Observation of spin Seebeck effect and developmenet in new materials, Spanish Team: Ibarra Group (University of Zaragoza): Development in thin films and devices.

SLIDE 3

electron

Spin: ±ħ/2 Charge: e

Spin current

Both spin current and charge current → Spin-electronics (Spintronics)

(usual electronics ← charge current）

Electron:

Charge current (Current)

SLIDE 4

Seebeck effect :

heat electricity Thermopower

Large Seebeck effect (Q) & Small Resistivity (ρ) are required.

Seebeck effect was discovered in 1821.

Energy conversion from heat to electricity:

Thermo-electric material

SLIDE 5

Galileo: NASA's Spacecraft

Curiosity,…

Radioisotope Themroelectric Generator

SEIKO THERMIC
CITIZEN

ECO-DRIVE THERMO

(Radioisotope battery, Nuelear battery)

SLIDE 6

Thermo-electric materials: Heat→Electricity Electricity→Heat

Thermo-electric materials： No vibration (no moving part), Easy to miniaturize, Gentle to environment.

Garbage burning plant Heat of car Refrigerator

SLIDE 7

Wine Cellar: no vibration

Panasonic’s product:

SLIDE 8

spin-Seebeck effect

J J

↑ ↓

− Spin current:

Electric voltage “Spin voltage” Electric current flows!

Spin current flows!

SLIDE 9

ASRC Colloquium

= =

+

=

Electric current Electric current & Spin current Spin current

SLIDE 10

Charge current Spin current carried by conduction electrons

J J J

↑ ↓

= +

J J J

↑ ↓

= −

SLIDE 11

Spin current carried by spin waves

SLIDE 12

Spin Seebeck effect

Lower T end Higher T end Pt: spin detector

(4 mm x100 µm x10 nm)

NiFe: thermo-spin generator

(4 mm x6 mm x20 nm)

spin Hall effect: ESHE = DISHE Js × σ

magnitude & polarization of Js

K. Uchida et al.: Nature 455, 778 (2008)

(Saitoh Group, Maekawa Group)

SLIDE 13

YIG: Insulating ferrimagnet

Spin Seebeck effect: A common phenomenon in ferromagnets!!

K. Uchida et al.: Nature Mater. 9, 894 (2010).

SLIDE 14

Thermoelectric module

P N

T + ∆T T electric current electric current electric current

SLIDE 15

Spin Seebeck (thermoelectric) device

Kirihara et al., Nature Materials 11, 686 (2012) (NEC, Saitoh Gr. Maekawa Gr.)

SLIDE 16

Magnetite (Fe3O4)

P. Weiss and R. Forrer,
Ann. Phys. 12, 279(1929)
R. W. Millar,
J. Am. Chem. Soc. 51, 215(1929)
T. Okamura, Sci. Rep.

Tohoku Imp. Univ. 21, 231(1932)

Metal-Insulator Transition at 120K! insulator

Metal

Magnetite thin films Developed by U. of Zaragoza

SLIDE 17

R. Ramos et al.: Phys. Rev. B (2013)

SLIDE 18

JST Japan-Spain Collaboration: “Development in Spin Seebeck Devices” Japanese Team: Maekawa Group (ASRC, JAEA, Tokai): Theory of spin Seebeck effect, Saitoh Group (IMR, Tohoku University, Sendai): Observation of spin Seebeck effect and developmenet in new materials, Spanish Team: Ibarra Group (University of Zaragoza): Development in thin films and devices. Spin Seebeck devices with magnetite!!