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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Magnetic, structural, and transport properties at very high temperature in manganites

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Author(s):
Nima Ramirez, Fabian Enrique [1] ; Ferreira, Fabio Furlan [1] ; Alves, Wendel Andrade [1] ; Queiruga Rey, Jose Fernando [1] ; Souza, Jose Antonio [1]
Total Authors: 5
Affiliation:
[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09090400 Santo Andre, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Journal of Magnetism and Magnetic Materials; v. 324, n. 13, p. 2011-2018, JUL 2012.
Web of Science Citations: 3
Abstract

Magnetic, structural, and electric transport measurements at high temperatures were carried out on La1-xCaxMnO3; x=0.20, 0.25, 0.30, 0.34, 0.40, and 0.45. All samples show a first-order structural phase transition from orthorhombic Pnma to rhombohedral R (3) over barc space group at TR-O. Magnetic susceptibility measurements show that the Curie-Weiss law is strictly obeyed in the rhombohedral phase as opposed to the orthorhombic phase where the effective magnetic moment has a temperature dependence. The electrical resistivity is well described by the small polaron hopping mechanism in the samples up to x=0.34. As the charge carriers are introduced into the system (x=0.40 and 0.45), this mechanism of hopping ceases to be valid. The value of Gruneisen parameter obtained through analysis of high-resolution X-ray powder diffraction as a function of temperature increases abruptly for the sample with x=0.40. This is consistent with an increase in bending and stretchinglike frequency modes observed by Raman spectroscopy. (C) 2012 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 09/18618-5 - Synthesis and characterization of thermodynamic and electrical transport properties of advanced materials
Grantee:José Antonio Souza
Support Opportunities: Regular Research Grants
FAPESP's process: 10/18364-0 - Physical properties and critical phenomena in strong correlated systems.
Grantee:Fabian Enrique Nima Ramirez
Support Opportunities: Scholarships in Brazil - Doctorate