Study of magnetoresistance and conductance of bicrystal grain boundary in La0.67Ba0.33MnO3 thin film

Khare, Neeraj and Gupta, AK and Moharil, UP and Raychaudhuri, AK and Pai, SP and Pinto, R (2002) Study of magnetoresistance and conductance of bicrystal grain boundary in La0.67Ba0.33MnO3 thin film. In: Pramana - Journal of Physics, 58 (5-6). pp. 1165-1170.

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Abstract

La0.67Ba0.33MnO3 (LBMO) thin film is deposited on a 36.7degrees SrTiO3 bicrystal substrate using laser ablation technique. A microbridge is created across bicrystal grain boundary and its characteristics are compared with a microbridge on the LBMO film having no grain boundary. Presence of grain boundary exhibits substantial magnetoresistance ratio (MRR) in the low field and low temperature region. Bicrystal grain boundary contribution in MRR disappears at temperature T > 175 K. At low temperature, I-V characteristic of the microbridge across bicrystal grain boundary is nonlinear. Analysis of temperature dependence of dynamic conductance-voltage characteristics of the bicrystal grain boundary indicates that at low temperatures (T < 175 K) carrier transport across the grain boundary in LBMO film is dominated by inelastic tunneling via pairs of manganese atoms and tunneling through disordered oxides. At higher temperatures (T > 175 K), magnetic scattering process is dominating. Decrease of bicrystal grain boundary contribution in magnetoresistance with the increase in temperature is due to enhanced spin-flip scattering process.

Item Type:	Journal Article
Publication:	Pramana - Journal of Physics
Publisher:	Indian Academy of Sciences
Additional Information:	Copyright of this article belongs to Indian Academy of Sciences.
Keywords:	Colossal magnetoresistance;bicrystal junction;grain boundary; LBMO;spin-polarized tunneling.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	28 Jul 2011 05:37
Last Modified:	13 Nov 2018 15:26
URI:	http://eprints.iisc.ac.in/id/eprint/39427

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