Magnetic Field Melting of the Charge-Ordered State of La0.5Ca0.5MnO3: A Local Structure Perspective

Abstract

The local structure about the Mn site in the half doped system La0.5Ca0.5MnO3 was measured in magnetic fields up 10 T to probe the melting of the charge ordered state. Examination of the Mn-O and Mn-Mn correlations reveal three distinct regions in the structure-field diagram. A broad region with weak field dependence (mainly antiferromatnetic phase below 7.5 T), a narrow-mixed phase region near ~ 8.5 T followed by a ferromagnetic phase region with strong field-structure coupling. At high field the Mn-O radial distribution becomes Gaussian and the Mn-Mn correlations are enhanced - consistent with the dominance of a ferromagnetic phase. The exponential change in resistivity in the first region (observed in transport measurements) is dominated by the reordering of the moments on the Mn sites from CE type antiferromagnetic to ferromagnetic order with only a weak change in the local distortions of the MnO6 octahedra.

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Cited by in corpus (5)

• Neutron diffraction evidence for kinetic arrest of first-order magneto-structural phase transitions in some functional magnetic materials
• Doping and Field-Induced Insulator-Metal Transitions in Half-Doped Manganites
• Raman scattering studies of temperature- and field-induced melting of charge order in (La,Pr,Ca)MnO${}_3$
• Local Structure of Multiferroic TbMn2O5: Evidence for an Anomalous Terbium Oxygen Distribution
• Instabilities and Insulator-Metal transitions in Half-Doped Manganites induced by Magnetic-Field and Doping