skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Manipulation of pure spin current in ferromagnetic metals independent of magnetization

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Spins and Heat in Nanoscale Electronic Systems (SHINES)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1388938
DOE Contract Number:
SC0012670
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review B; Journal Volume: 94; Journal Issue: 2; Related Information: SHINES partners with University of California, Riverside (lead); Arizona State University; Colorado State University; Johns Hopkins University; University of California Irvine; University of California Los Angeles; University of Texas at Austin
Country of Publication:
United States
Language:
English
Subject:
phonons, thermal conductivity, thermoelectric, spin dynamics, spintronics

Citation Formats

Tian, Dai, Li, Yufan, Qu, D., Huang, S. Y., Jin, Xiaofeng, and Chien, C. L. Manipulation of pure spin current in ferromagnetic metals independent of magnetization. United States: N. p., 2016. Web. doi:10.1103/PhysRevB.94.020403.
Tian, Dai, Li, Yufan, Qu, D., Huang, S. Y., Jin, Xiaofeng, & Chien, C. L. Manipulation of pure spin current in ferromagnetic metals independent of magnetization. United States. doi:10.1103/PhysRevB.94.020403.
Tian, Dai, Li, Yufan, Qu, D., Huang, S. Y., Jin, Xiaofeng, and Chien, C. L. 2016. "Manipulation of pure spin current in ferromagnetic metals independent of magnetization". United States. doi:10.1103/PhysRevB.94.020403.
@article{osti_1388938,
title = {Manipulation of pure spin current in ferromagnetic metals independent of magnetization},
author = {Tian, Dai and Li, Yufan and Qu, D. and Huang, S. Y. and Jin, Xiaofeng and Chien, C. L.},
abstractNote = {},
doi = {10.1103/PhysRevB.94.020403},
journal = {Physical Review B},
number = 2,
volume = 94,
place = {United States},
year = 2016,
month = 7
}
  • Spin electronic structure of the Graphene/Pt interface has been investigated. A large induced spin-orbit splitting (∼80 meV) of graphene π states with formation of non-degenerated Dirac-cone spin states at the K{sup ¯}-point of the Brillouin zone crossed with spin-polarized Pt 5d states at Fermi level was found. We show that this spin structure can be used as a spin current source in spintronic devices. By theoretical estimations and micromagnetic modeling based on the experimentally observed spin-orbit splitting, we demonstarte that the induced intrinsic magnetic field in such structure might be effectively used for induced remagnetization of the (Ni-Fe)-nanodots arranged atop themore » interface.« less
  • Using ferromagnetic (FM) resonance spin pumping, we observe injection of spin currents from Y{sub 3}Fe{sub 5}O{sub 12} (YIG) films to FM metals, including Ni{sub 81}Fe{sub 19} (Py), Fe, Co, and Ni, and detection of spin currents by inverse spin Hall effect (ISHE) in the FM metals. We obtain a high effective spin mixing conductance of 6.3 × 10{sup 18} m{sup −2} in a YIG/Cu/Py trilayer and a spin Hall angle of 0.020 for Py. The spin pumping signals in Fe, Co, and Ni confirm the mechanism of ISHE in FMs is the inverse process of the anomalous Hall effect.
  • Strong spin-orbit coupling in non-magnetic heavy metals has been shown to lead to large spin currents flowing transverse to a charge current in such a metal wire. This in turn leads to the buildup of a net spin accumulation at the lateral surfaces of the wire. Spin-orbit torque effects enable the use of the accumulated spins to exert useful magnetic torques on adjacent magnetic layers in spintronic devices. We report the direct detection of spin accumulation at the free surface of nonmagnetic metal films using magnetization-induced optical surface second harmonic generation. The technique is applied to probe the current inducedmore » surface spin accumulation in various heavy metals such as Pt, β-Ta, and Au with high sensitivity. The sensitivity of the technique enables us to measure the time dynamics on a sub-ns time scale of the spin accumulation arising from a short current pulse. The ability of optical surface second harmonic generation to probe interfaces suggests that this technique will also be useful for studying the dynamics of spin accumulation and transport across interfaces between non-magnetic and ferromagnetic materials, where spin-orbit torque effects are of considerable interest.« less
  • In order to elucidate room-temperature (RT) ferromagnetism (FM) in ZnO, we have analyzed a multitude of experimental publications with respect to the ratio of grain-boundary (GB) area to grain volume. FM only appears if this ratio exceeds a certain threshold value s{sub th}. Based on these important results nanograined pure and Mn-doped ZnO films have been prepared, which reveal reproducible RT FM and magnetization proportional to the film thickness, even for pure ZnO films. Our findings strongly suggest that grain boundaries and related vacancies are the intrinsic origin for RT ferromagnetism.