Distribution of magnetic moments in Co/Pt and Co/Pt/Ir/Pt multilayers detected by magnetic x‐ray absorption

1993 ◽  
Vol 73 (10) ◽  
pp. 6430-6432 ◽  
Author(s):  
G. Schütz ◽  
S. Stähler ◽  
M. Knülle ◽  
P. Fischer ◽  
S. Parkin ◽  
...  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fridtjof Kielgast ◽  
Ivan Baev ◽  
Torben Beeck ◽  
Federico Pressacco ◽  
Michael Martins

AbstractMass-selected V and Fe monomers, as well as the heterodimer $${\text{Fe}}_1{\text{V}}_1$$ Fe 1 V 1 , were deposited on a Cu(001) surface. Their electronic and magnetic properties were investigated via X-ray absorption (XAS) and X-ray magnetic circular dichroism (XMCD) spectroscopy. Anisotropies in the magnetic moments of the deposited species could be examined by means of angle resolving XMCD, i.e. changing the X-ray angle of incidence. A weak adatom-substrate-coupling was found for both elements and, using group theoretical arguments, the ground state symmetries of the adatoms were determined. For the dimer, a switching from antiparallel to parallel orientation of the respective magnetic moments was observed. We show that this is due to the existence of a noncollinear spin-flop phase in the deposited dimers, which could be observed for the first time in such a small system. Making use of the two magnetic sublattices model, we were able to find the relative orientations for the dimer magnetic moments for different incidence angles.


2020 ◽  
Vol 31 (08) ◽  
pp. 2050109
Author(s):  
S. Uba ◽  
A. Bonda ◽  
L. Uba ◽  
L. V. Bekenov ◽  
V. N. Antonov

Electronic structure, X-ray absorption, and magnetic circular dichroism (XMCD) spectra in the CoFeMnSi Heusler alloy were studied from first principles. Fully relativistic Dirac linear muffin-tin orbital band structure method was implemented with various exchange–correlation functionals tested. The supercell approach was used to study the influence of intersite disorder, at the levels of 6.25%, 12.5%, and 25% within transition metal sites, on the XMCD spectra at [Formula: see text] edges and spin polarization (SP) at the Fermi level. It is found that most sensitive to Fe–Mn and Co–Fe disorder are XMCD spectra at [Formula: see text] edges of Fe, while the sensitivity decreases from Mn to Co. It is shown that magnetic moments estimated with the use of magneto-optical (MO) sum rules agree with the ab initio calculated ones to within [Formula: see text], [Formula: see text], and [Formula: see text], for Co, Fe, and Mn, respectively. The calculated SP decreases from 99% for ordered CoFeMnSi alloy, to 96% upon 25% Co–Fe disorder, to 83% for Fe–Mn disorder, and to 42% in the case of Co–Mn disorder. The calculated spectra agree well with the available experimental data. The rich XMCD spectral structures are predicted from first principles at Fe, Co, Mn and Si [Formula: see text] edges.


2007 ◽  
Vol 1050 ◽  
Author(s):  
Gerhard Jakob ◽  
Tobias Eichhorn ◽  
Michael Kallmayer ◽  
Hans-Joachim Elmers

AbstractA magnetically induced shape memory effect in Ni2MnGa results in huge magnetostrictive effects of several percent. Using x-ray absorption spectroscopy (XAS) and magnetic circular dichroism (XMCD) we investigated element specific magnetic moments and electronic structure of single crystalline, (110) oriented Ni2MnGa films on a-plane Al2O3 substrates in the austenite and martensite state. The structural phase transition of the samples is evident from temperature dependent x-ray diffraction and magnetization measurements. The Ni XAS differ significantly for temperatures above and below the martensite transition in agreement with published ab-initio calculations. Using XAS in transmission geometry on our thin film samples we observe the corresponding reduction of the absorption feature as predicted by theoretical calculations. The XMCD analysis shows the orbital contribution of the Ni electrons to be responsible for the magnetic anisotropy.


1994 ◽  
Vol 50 (10) ◽  
pp. 7157-7160 ◽  
Author(s):  
Jan Vogel ◽  
Giancarlo Panaccione ◽  
Maurizio Sacchi

SPIN ◽  
2014 ◽  
Vol 04 (04) ◽  
pp. 1440017 ◽  
Author(s):  
GERHARD H. FECHER ◽  
DANIEL EBKE ◽  
SIHAM OUARDI ◽  
STEFANO AGRESTINI ◽  
CHANG-YANG KUO ◽  
...  

The half-metallic Heusler compound Co2MnSi is a very attractive material for spintronic devices because it exhibits very high tunnelling magnetoresistance ratios. This work reports on a spectroscopic investigation of thin Co2MnSi films as they are used as electrodes in magnetic tunnel junctions. The investigated films exhibit a remanent in-plane magnetization with a magnetic moment of about 5 μBwhen saturated, as expected. The low coercive field of only 4 mT indicates soft magnetic behavior. Magnetic dichroism in emission and absorption was measured at the Co and Mn  2p core levels. The photoelectron spectra were excited by circularly polarized hard X-rays with an energy of 6 keV and taken from the remanently magnetized film. The soft X-ray absorption spectra were taken in an induction field of 4 T. Both methods yielded large dichroism effects. An analysis reveals the localized character of the electrons and magnetic moments attributed to the Mn atoms, whereas the electrons related to the Co atoms contribute an itinerant part to the total magnetic moment.


1991 ◽  
Vol 231 ◽  
Author(s):  
G. Schütz ◽  
H. Ebert ◽  
P. Fischer ◽  
S. Rüegg ◽  
W. B. Zeper

AbstractLocal d-magnetic moments of the Pt interlayer in Pt/Co multilayered structures (4 ÅCo + X ÅPt, X=9,19,23,30,40) have been investigated theoretically and experimentally by circular magnetic x-ray dichroism studies.It has been found that a significant Pt polarization is induced, which contributes by about 13% to the total magnetization. The experimental findings of the average Pt moments agree well with the theoretical expectations indicating the existence of a longrange exchange coupling through the Pt layer.


1993 ◽  
Vol 121 (1-3) ◽  
pp. 234-237 ◽  
Author(s):  
S. Stähler ◽  
G. Schütz ◽  
P. Fischer ◽  
M. Knülle ◽  
S. Rüegg ◽  
...  

2002 ◽  
Vol 09 (02) ◽  
pp. 955-960 ◽  
Author(s):  
A. YAMASAKI ◽  
S. IMADA ◽  
S. SUGA ◽  
T. KANOMATA ◽  
S. ISHIDA

Magnetic circular dichroism (MCD) of core-level absorption spectra (XAS) in the soft X-ray region has been measured for the ferromagnetic Heusler alloys Co 2 TiSn , Co 2 ZrSn , and Co 2 NbSn . The Co 2p → 3d XAS–MCD spectra show an obvious contribution of the orbital angular momentum component to the magnetic moment in these alloys. The ratio between the orbital and the spin magnetic moments derived from the MCD spectra varies by more than a factor of 2 within these alloys. The mechanism of this variation is discussed in comparison with the band structure calculation.


RSC Advances ◽  
2015 ◽  
Vol 5 (25) ◽  
pp. 19014-19019 ◽  
Author(s):  
K. Saravanan ◽  
C.-H. Kao ◽  
Y.-C. Shao ◽  
Y.-F. Wang ◽  
B.-Y. Wang ◽  
...  

Strong perpendicular magnetic anisotropy (PMA) is observed in annealed Pd/Co/Pd trilayer film. The effect of temperature on alloy formation, the relationship among the atomic/electronic structures, magnetic moments and PMA has been studied.


Sign in / Sign up

Export Citation Format

Share Document