Percolative transition on ferromagnetic insulator manganites: Uncorrelated to correlated polaron clusters

2004/08/31 by A. M. L. Lopes, J. P. Araujo, João P. Araújo +7 · 1 citation
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Rare-earth and actinide compounds #cond-mat.str-el

paper · pdf · doi:10.1103/physrevb.73.100408

published as Phys. Rev. B (Rapid Comm) 73, 100408(R) (2006) · 4 pages, 4 Figures, submitted to PRL, new version with more data, text reformulated

arxiv created 2005/11/03 · openalex publication_date 2006/03/24 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

We report an atomic-scale study on the ferromagnetic insulator manganite LaMnO_3.12 using \ensuremathγ\text\ensuremath-\ensuremathγ perturbed angular correlation spectroscopy. Data analysis reveals a nanoscopic transition from an undistorted to a Jahn-Teller (JT) distorted local environment upon cooling. The percolation thresholds of the two local environments enclose a macroscopic structural transition (rhombohedral-orthorhombic). Two distinct regimes of JT distortions were found: a high-temperature regime where uncorrelated polaron clusters with severe distortions of the Mn³⁺O₆ octahedra survive up to T\ensuremath≈800\phantom\rule0.3em0exK and a low-temperature regime where correlated regions have a weaker JT-distorted symmetry.

Citations

• Raman phonons as a probe of disorder, fluctuations, and local structure in doped and undoped orthorhombic and rhombohedral manganites

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