Spin state transition in LaCoO3 studied using soft x-ray absorption spectroscopy and magnetic circular dichroism.
Using soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co-L(2,3) edge, we reveal that the spin state transition in LaCoO3 can be well described by a low-spin ground state and a triply degenerate high-spin first excited state. From the temperature dependence of the spectral line shapes, we find that LaCoO3 at finite temperatures is an inhomogeneous mixed-spin state system. It is crucial that the magnetic circular dichroism signal in the paramagnetic state carries a large orbital momentum. This directly shows that the currently accepted low- or intermediate-spin picture is at variance. Parameters derived from these spectroscopies fully explain existing magnetic susceptibility, electron spin resonance, and inelastic neutron data.
Haverkort
M W
MW
II. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
Hu
Z
Z
Cezar
J C
JC
Burnus
T
T
Hartmann
H
H
Reuther
M
M
Zobel
C
C
Lorenz
T
T
Tanaka
A
A
Brookes
N B
NB
Hsieh
H H
HH
Lin
H-J
HJ
Chen
C T
CT
Tjeng
L H
LH