The European Physical Journal B

, 85:260

Large magnetoresistance and Jahn-Teller effect in Sr2FeCoO6

Authors

  • R. Pradheesh
    • Low Temperature Physics Laboratory, Department of Physics, Indian Institute of Technology Madras
  • Harikrishnan S. Nair
    • Jülich Center for Neutron Sciences 2/ Peter Grünberg Institute 4, Forschungszentrum Jülich GmbH
  • V. Sankaranarayanan
    • Low Temperature Physics Laboratory, Department of Physics, Indian Institute of Technology Madras
  • K. Sethupathi
    • Low Temperature Physics Laboratory, Department of Physics, Indian Institute of Technology Madras
Regular Article

DOI: 10.1140/epjb/e2012-30264-2

Cite this article as:
Pradheesh, R., Nair, H.S., Sankaranarayanan, V. et al. Eur. Phys. J. B (2012) 85: 260. doi:10.1140/epjb/e2012-30264-2

Abstract

Neutron diffraction measurement on the spin glass double perovskite Sr2FeCoO6 reveals site disorder as well as Co3+ intermediate spin state. In addition, multiple valence states of Fe and Co are confirmed through Mössbauer and X-ray photoelectron spectroscopy. The structural disorder and multiple valence lead to competing ferromagnetic and antiferromagnetic interactions and subsequently to a spin glass state, which is reflected in the form of an additional T-linear contribution at low temperatures in specific heat. A clear evidence of Jahn-Teller distortion at the Co3+–O6 complex is observed and incorporating the physics of Jahn-Teller effect, the presence of localized magnetic moment is shown. A large, negative and anomalous magnetoresistance of  ≈63% at 14 K in 12 T applied field is observed for Sr2FeCoO6. The observed magnetoresistance could be explained by applying a semi-empirical fit consisting of a negative and a positive contribution and show that the negative magnetoresistance is due to spin scattering of carriers by localized magnetic moments in the spin glass phase.

Keywords

Solid State and Materials

Copyright information

© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2012