Metal-Insulator Transitions in Anion-Excess LaMnO3+? Controlled by the Mn4+ Content

Verelst, M and Rangavittal, N and Rao, CNR and Rousset, A (1993) Metal-Insulator Transitions in Anion-Excess LaMnO3+? Controlled by the Mn4+ Content. In: Journal of Solid State Chemistry, 104 (1). pp. 74-80.

PDF Metal.pdf - Published Version Restricted to Registered users only Download (219kB) | Request a copy

Abstract

LaMnO3+? samples with Mn4+ content up to 50% have been prepared by different methods. The structure of LaMnO3+? changes from orthorhombic to cubic (via rhombohedral) with increase in the Mn4+ content. LaMnO3+? samples containing greater than 20% Mn4+ are ferromagnetic and show resistivity maxima at a temperature Tt which is close to the ferromagnetic Curie temperature. The resistivity maximum is due to the occurrence of a metal-insulator transition. In samples heated to the same temperature, the value of Tt increases with % Mn4+. For a given sample, Tt increases with the temperature of heat treatment due to the increase in particle size. The onset of ferromagnetism in LaMnO3+? accompanied by an insulator-metal transition is similar to that found in La1-xCaxMnO3 and La1-xSrxCoO3.

Item Type:	Journal Article
Publication:	Journal of Solid State Chemistry
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	14 Mar 2011 08:48
Last Modified:	14 Mar 2011 08:48
URI:	http://eprints.iisc.ac.in/id/eprint/35608

Actions (login required)

View Item