Eur. Phys. J. B 47, 221-229 (2005)
https://doi.org/10.1140/epjb/e2005-00311-4

Mössbauer study of 1% ⁵⁷Fe doped ferromagnetic insulator La_0.825Ca_0.175MnO₃

¹ Institute of Materials Science, NCSR, Demokritos, 15310 Aghia Paraskevi, Athens, Greece
² Department of Physics, National Technical University of Athens, 157 80 Athens, Greece

Corresponding author: ^a mpissas@ims.demokritos.gr

Received: 21 July 2004
Revised: 11 May 2005
Published online: 11 October 2005

Abstract

We have employed magnetization measurements, Mössbauer and ESR spectroscopic techniques, in order to study the ferromagnetic insulating (FMI) compound LaCa_xMnO₃ (x=0.175) doped with 1% ⁵⁷Fe. We have used two samples; one prepared in air which has cation vacancies and a second in inert atmosphere, which is stoichiometric. An abrupt change of the experimental results is obtained, by all techniques, in the ferromagnetic insulating regime, in the temperature region of  K, where an orbital rearrangement is suggested to occur. An analysis of these findings points to an orbital rearrangement transformation. Ferromagnetic resonance reveals considerable differences between stoichiometric and cation deficient samples, indicating anisotropy of the exchange interactions in the former sample with significant temperature dependence, most pronounced in the vicinity of