Electron paramagnetic resonance EXAFS Magnetically ordered materials Spin-lattice interaction
Issue Date:
2003
Publisher:
Physica B: Condensed Matter
Citation:
Volume 327, Issue 4-Feb, Page 183-186
Abstract:
Extended X-ray absorption fine structure (EXAFS) analysis and electron-paramagnetic resonance
(EPR) have been used to examine the local structure and the internal dynamics of La0.6Sr0.2Ca0.2MnO3
and La0.6Sr0.2Ba0.2MnO3 lanthanum manganites. The Mn-O bond distance (? 1.94 ?? for both samples)
and the Debye-Waller factors (0.36 ?? 10-2 and 0.41 ?? 10-2??2 for La0.6Sr0.2Ca0.2MnO3 and for La0.6Sr
0.2Ba0.2MnO3, respectively) were obtained from the EXAFS analysis. The dependence of the EPR line
width on dopant kind (Ca or Ba) showed a decrease of the spin-lattice interaction with an increase of the
Curie temperature. For both compositions, the EPR line intensity followed the exponential law I(T) = I0
exp(Ea/kBT), deduced on the basis of the adiabatic polaron hopping model. ?? 2002 Elsevier Science B.V.
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