Magnetic circular x-ray dichroism in transverse geometry: A new tool to study the magnetocrystalline anisotropy

1997 ◽  
Vol 81 (8) ◽  
pp. 5355-5357 ◽  
Author(s):  
H. A. Dürr ◽  
G. van der Laan
1983 ◽  
Vol 21 ◽  
Author(s):  
M. Doukoure ◽  
D. Gignoux ◽  
F. Sayetat

ABSTRACTHoAlGa is hexagonal at room temperature. It undergoes two magnetic transitions succesively at TN = 32 K from a paramagnetic to a triangular antiferromagnetic state where the Ho moments lie in the basal plane and at Tt = 18 K in the course of which the moments rotate toward c giving rise to a colinear antiferromagnetic arrangement. X-ray experiments performed between 5 and 300 K allow to determine the crystal evolution through the two transitions. The hexagonal symmetry is not lowered through the transitions; this result is compatible with the observed magnetic groups. The thermal expansion curves show a very anisotropic behaviour of the lattice parameters. The “c” parameter shrinks below TN and this anomaly is to be related to the magnetic order. Along a, a positive thermal anomaly appears below 70 K and this can be interpreted by crystal field effects. Stability of magnetic structures is discussed with regard to exchange interactions and magnetocrystalline anisotropy.


2012 ◽  
Vol 26 (26) ◽  
pp. 1250141 ◽  
Author(s):  
Y. B. HAN ◽  
J. SHA ◽  
L. N. SUN ◽  
Q. TANG ◽  
Q. LU ◽  
...  

Sm (Co or/and Zn) substituted nanocrystalline barium hexaferrites were synthesized by the sol–gel auto-combustion process, then X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) were used to characterize and discuss the phase composition and the magnetic properties of the as-prepared barium hexaferrites. All results showed that the phase composition and magnetic properties were closely related to the doping elements and x. Owing to hyperfine field, canting spin, magnetic dilution and impurity phases, the saturation magnetization (Ms) of all samples increased firstly, and then decreased. Considering the crystallization, the magnetocrystalline anisotropy and the ions occupancy, the doping elements and x critically affected the coercivity (Hc). Compared the magnetic properties of all the samples, it is concluded that Zn 2+ and Co 2+ influenced each other and Zn 2+ occupied 4f2 sites prior to Co 2+, which led to the increase of Ms and the decrease of Hc.


1998 ◽  
Vol 58 (10) ◽  
pp. 6298-6304 ◽  
Author(s):  
W. Grange ◽  
M. Maret ◽  
J.-P Kappler ◽  
J. Vogel ◽  
A. Fontaine ◽  
...  

2012 ◽  
Vol 529 ◽  
pp. 590-593
Author(s):  
Hong Bo Zhang ◽  
Fu Gang Shen ◽  
Tao Yang

The crystal structure, Curie temperatures, spin reorientation temperature, magnetocrystalline anisotropy constant and magnetostriction of TbDyHoFe1.95 alloys with composition formulation (1-y)Tb0.36Dy0.64Fe1.95+yTb0.20Dy0.22Ho0.58Fe1.95 (0≤y≤1) were investigated. X-ray diffraction patterns demonstrate the TbDyHoFe1.95 alloys possess MgCu2-type cubic Laves structure. The Curie temperature Tc decreases slightly from 381 °C for Tb0.36Dy0.64Fe2 to 379 °C for y=0.3, 375°C for y=0.4 and 373°C for y=0.5. The spin reorientation temperature Tr increases from -94 oC for Tb0.36Dy0.64Fe2 to -70°C for y=0.3 and -51oC for y=0.5. The magnetocrystalline anisotropy constant K1 decreases with increasing y value. The magnetostriction was examined under applied magnetic field H (0


2015 ◽  
Vol 233-234 ◽  
pp. 571-574
Author(s):  
V.G. Myagkov ◽  
L.E. Bykova ◽  
V.S. Zhigalov ◽  
I.A. Tambasov ◽  
G.N. Bondarenko ◽  
...  

The solid-state reaction between epitaxial hcp-Co (110) and fcc-Co (001) thin films and Pd layers was investigated at annealing temperatures between 250 and 650 °C using X-ray diffraction and magnetic measurements. No significant intermixing of the layers occurs at annealing temperatures below 400 °C. For the atomic composition 1Co:1Pd after annealing at 450 °C the disordered solid solution fcc-CoxPd1-x is formed on the Pd/hcp-Co (110) and Pd/fcc-Co (001) interfaces. Epitaxial relationships CoPd (110)〈-111〉 || MgO(001)〈100〉 and CoPd (001)〈100〉 || MgO(001)〈100〉 between the nucleated disordered phase CoPd and the substrate MgO(001) were determined for Pd/hcp-Co (110) and Pd/fcc-Co (001) bilayers, respectively. The first magnetocrystalline anisotropy constant of the disordered CoPd phase ​​K1CoPd = - (1.8 ± 0.4)·104 J/m3 for the (110) and (001) orientations was obtained.


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