Enhanced orbital magnetism in Fe(50)Pt(50) nanoparticles.
X-ray absorption and magnetic circular dichroism spectra at both the Fe and Pt L(3,2) edges were measured on wet-chemically synthesized monodisperse Fe(50)Pt(50) particles with a mean diameter of 6.3 nm before and after complete removal of the organic ligands and the oxide shell covering the particles by soft hydrogen plasma resulting in a pure metallic state. After thermal treatment of the metallic particles, the coercive field increased by a factor of 6, the orbital magnetic moment at the Fe site increased by 330% and is reduced at the Pt site by 30%, while the effective spin moments did not change. A decrease of the frequency of oscillations in the extended x-ray absorption fine structure at the Pt L(3,2) edges provides evidence for crystallographic changes towards the L1(0) phase.
Antoniak
C
C
Experimentalphysik-AG Farle, Fachbereich Physik, Universität Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany.
Lindner
J
J
Spasova
M
M
Sudfeld
D
D
Acet
M
M
Farle
M
M
Fauth
K
K
Wiedwald
U
U
Boyen
H-G
HG
Ziemann
P
P
Wilhelm
F
F
Rogalev
A
A
Sun
Shouheng
S