Evidence for Spin Polarization of Metallic Copper in CO/Cu and Fe/Cu Multilayers

1993 ◽  
Vol 313 ◽  
Author(s):  
S. Pizzini ◽  
C. Giorgetti ◽  
A. Fontaine ◽  
E. Dartyge ◽  
G. Krill ◽  
...  
Keyword(s):  
Spin Polarization ◽  
Metallic Copper ◽  
Magnetic Element ◽  
X Ray ◽  
Conduction Electrons ◽  
Magnetic Layers ◽  
Spin Polarized

ABSTRACTMagnetic circular x-ray dichroism measurements on CO/Cu and Fe/Cu Multilayers at the K edge of copper show that the 4p -states of copper are significantly spin-polarized by the adjacent magnetic layers. In relation to the phase opposition of the copper thickness-dependent magnetoresistance of CO/Cu and Fe/Cu Multilayers it is of prime importance to notice that the polarization of the conduction electrons of copper follows specifically the polarization of the conduction electrons of the adjacent magnetic element.

Spin polarization in magnets

2017 ◽  
Author(s):  
K. Takanashi ◽  
Y. Sakuraba
Keyword(s):  
Spin Polarization ◽  
Spin Current ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Energy Band Gap ◽  
Magnetoresistance Effect ◽  
Half Metals ◽  
Conduction Electrons ◽  
Spin Polarized ◽  
Spin Dependent Scattering

This chapter explains how the exchange splitting between up- and down-spin bands in ferromagnets unexceptionally generates spin-polarized electronic states at the Fermi energy. The quantity of spin polarization P in ferromagnets is one of the important parameters for application in spintronics, since a ferromagnet having a higher P is able to generate larger various spin-dependent effects such as the magnetoresistance effect, spin transfer torque, spin accumulation, and so on. However, the spin polarizations of general 3d transition metals or alloys generally limit the size of spin-dependent effects. Thus,“‘half-metals” attract much interest as an ideal source of spin current and spin-dependent scattering because they possess perfectly spin-polarized conduction electrons due to the energy band gap in either the up- or down-spin channel at the Fermi level.

Optical Pumping of Spin-Polarized Conduction Electrons and Inelastic Scattering by Neutral Acceptors

1973 ◽  
Vol 51 (7) ◽  
pp. 718-723 ◽  
Author(s):  
R. R. Parsons
Keyword(s):  
Inelastic Scattering ◽  
Spin Polarization ◽  
Optical Pumping ◽  
Polarized Light ◽  
Energy Relaxation ◽  
Degree Of Polarization ◽  
Conduction Band Edge ◽  
Circularly Polarized Light ◽  
Conduction Electrons ◽  
Spin Polarized

The energy relaxation mechanisms of conduction electrons in p-type GaSb at 1.9 °K are investigated by an optical pumping technique. Spin-polarized electrons are excited across the forbidden band gap with circularly polarized light. The number of photocreated electrons is obtained from the intensity of the photoluminescence; and the spin polarization from the degree of polarization of the photoluminescence. The experiment shows that the number of electrons and the spin polarization at the conduction band edge depend on the initial energy of the electrons and on the number of neutral acceptors. An explanation of the results is given in terms of two processes of energy relaxation for conduction electrons: (i) the emission of longitudinal optical phonons, and (ii) inelastic scattering by neutral acceptors.

scholarly journals Magnetic dichroism in angular resolved hard X-ray photoelectron spectroscopy from buried magnetic layers

2013 ◽  
Vol 189 ◽  
pp. 146-151 ◽  
Author(s):  
Carlos E. ViolBarbosa ◽  
Siham Ouardi ◽  
Gerhard H. Fecher ◽  
Daniel Ebke ◽  
Claudia Felser
Keyword(s):  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Magnetic Dichroism ◽  
Magnetic Layers

High Spin Polarization of Conduction Band Electrons in GaAs-GaAsP Strained Layer Superlattice Fabricated as a Spin-Polarized Electron Source

2004 ◽  
Vol 43 (6A) ◽  
pp. 3371-3375 ◽  
Author(s):  
Tetsuya Matsuyama ◽  
Hisaya Takikita ◽  
Hiromichi Horinaka ◽  
Kenji Wada ◽  
Tsutomu Nakanishi ◽  
...  
Keyword(s):  
Conduction Band ◽  
Spin Polarization ◽  
High Spin ◽  
Electron Source ◽  
Strained Layer ◽  
Spin Polarized ◽  
High Spin Polarization ◽  
Strained Layer Superlattice

XAFS and X-MCD spectroscopies with undulator gap scan

1998 ◽  
Vol 5 (3) ◽  
pp. 989-991 ◽  
Author(s):  
Andrei Rogalev ◽  
Vincent Gotte ◽  
Jose´ Goulon ◽  
Christophe Gauthier ◽  
Joel Chavanne ◽  
...  
Keyword(s):  
Energy Range ◽  
Absorption Spectroscopy ◽  
Emission Peak ◽  
Photon Statistics ◽  
Wide Energy Range ◽  
X Ray ◽  
Polarization Rate ◽  
Spin Polarized ◽  
Wide Energy ◽  
X Ray Absorption

The first experimental applications of the undulator gap-scan technique in X-ray absorption spectroscopy are reported. The key advantage of this method is that during EXAFS scans the undulator is permanently tuned to the maximum of its emission peak in order to maximize the photon statistics. In X-MCD or spin-polarized EXAFS studies with a helical undulator of the Helios type, the polarization rate can also be kept almost constant over a wide energy range.

Magnetoresistance and Structure of Granular Co/Ag Thin Films

1993 ◽  
Vol 313 ◽  
Author(s):  
Mary Beth Stearns ◽  
Yuanda Cheng
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Room Temperature ◽  
Magnetization Measurements ◽  
X Ray ◽  
Conduction Electrons ◽  
Low Field ◽  
Co Concentration ◽  
Microscopy Techniques ◽  
Substrate Temperatures

ABSTRACTSeveral series of CoxAg1-x granular thin films (-3000Å) were fabricated by coevapora-tion of Co and Ag in a dual e-beam UHV deposition system at varying substrate temperatures. These films have low field magnetoresistance values as large as 31% at room temperature and 65% at liquid N2 temperature. The structure of the films was determined using magnetization measurements as well as x-ray and various electron microscopy techniques. The composition was determined using Rutherford backscattering spectroscopy. The Magnetoresistance was measured at both room and liquid N2 temperatures.We deduce from the magnetization and RBS Measurements that the films consist of Co globules embedded in a Ag Matrix and that there is no appreciable mixing of the Co and Ag atoms in the films deposited at substrate temperatures ≥ 400°K. The size of the Co globules is seen to increase with increasing Co concentration and the maximum magnetoresistance occurs in those films having the smallest Ag thickness which provides magnetic isolation of the Co globules.We suggest that the large magnetoresistance of these films arises from the same mechanism which causes the low field magnetoresistance in pure ferromagnets, namely, the scattering of the highly polarized d conduction electrons of the Co at magnetic boundaries. The large increase in the room temperature magnetoresistance of the CO/Ag films as compared to those of pure 3d ferromagnetic films is due to the distance between the magnetic boundaries being reduced to a few nanometers, because of the small size of the single domain Co globules, as compared to a few microns in 3d ferromagnets.

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