2001/07/30 by V. Podzorov, Vitaly Podzorov, B. G. Kim +3 · 4 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Electronic and Structural Properties of Oxides #Magnetic and transport properties of perovskites and related materials #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.64.140406
Short paper, 4 figures, to appear in Rapid Communication
arxiv created 2001/07/30 · openalex publication_date 2001/09/19 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper, we report polarized optical microscopy and electrical transport studies of manganese oxides that reveal that the charge ordering transition in these compounds exhibits typical signatures of a martensitic transformation. We demonstrate that specific electronic properties of charge-ordered manganites stem from a combination of martensitic accommodation strain and effects of strong electron correlations. This intrinsic strain is strongly affected by the grain boundaries in ceramic samples. Consistently, our studies show a remarkable enhancement of low field magnetoresistance and the grain size effect on the resistivity in polycrystalline samples and suggest that the transport properties of this class of manganites are governed by the charge-disordered insulating phase stabilized at low temperature by virtue of martensitic accommodation strain. High sensitivity of this phase to strains and magnetic field leads to a variety of striking phenomena, such as unusually high magnetoresistance (1010%) in low magnetic fields.