Ordering of polarons in the charge-disordered phase of Pr 0.7 Ca 0.3 MnO 3
2009; American Physical Society; Volume: 79; Issue: 15 Linguagem: Inglês
10.1103/physrevb.79.153110
ISSN1550-235X
AutoresA. Levstik, C. Filipič, V. Bobnar, Anton Potočnik, Denis Arčon, Silvo Drnovšek, Janez Holc, Zvonko Jagličić,
Tópico(s)Multiferroics and related materials
Resumo${\text{Pr}}_{1\ensuremath{-}x}{\text{Ca}}_{x}{\text{MnO}}_{3}$ (PCMO, $x=0.3$) ceramic is a member of the manganite family that exhibits a colossal magnetoresistance. We report a comprehensive study of perovskite manganite PCMO $(x=0.3)$ ceramic with EPR, dielectric spectroscopy, and ac electrical conductivity. Activated-type temperature dependence of EPR linewidth is a strong signature for a hopping of Jahn-Teller polarons above $\ensuremath{\approx}150\text{ }\text{K}$. Analysis of the electrical conductivity and dielectric constant data suggests the ordering of polarons in the charge-disordered state of PCMO $(x=0.3)$ below 60 K. This provides a new understanding of the phase diagrams in PCMO systems.
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