Prasad, R. and Singh, M. P. and Siwach, P. K. and Kaur, A. and Fournier, P. and Singh, H. K. (2010) Effect of thickness on magnetic phase coexistence and electrical transport in Nd0.51Sr0.49MnO3 films. Applied Physics A , 99 (4). pp. 823-829. ISSN 1432-0630

PDF - Published Version Restricted to Registered users only Download (352Kb) | Request a copy

Abstract

We present the impact of the film thickness on the coexistence of various magnetic phases and its link to the magnetoresistance of Nd0.51Sr0.49MnO3 thin films. These epitaxial films are deposited on LaAlO3 (001) substrates by DC magnetron sputtering. Films with thicknesses of approximately 30 nm are found to be under full compressive strain while those with thicknesses ∼100 nm and beyond exhibit the presence of both strained and relaxed phases, as evidenced from X-ray diffraction studies. Both films exhibit multiple magnetic transitions controlled by strong electron correlations and phase coexistence. These films also display insulator–metal transitions (IMT) and colossal magnetoresistance (CMR) under moderate magnetic fields. Among the two set of films, only the 30-nm films show a weak signature of charge ordering at T ≈ 50 K. Even at temperatures much lower than the IMT, the 30-nm films show huge magnetoresistance (MR) ∼80%. This suggests presence of softened charge-ordered insulating (COI) clusters that are transformed into ferromagnetic metallic (FMM) ones by the external magnetic field. In the 100-nm films, the corresponding MR is suppressed to less than 20%. Our study demonstrates that the softening of the COI phase is induced by the combined effect of the in-plane compressive strain and a slight reduction in Sr concentration.

Item Type:	Article
Additional Information:	Copyright for this article belongs to Springer Science+Business Media.
Uncontrolled Keywords:	Doped manganites; Thin films; Phase coexistence; Magnetoresistance
Subjects:	Materials Science Physics
Divisions:	UNSPECIFIED
Depositing User:	Ms Neetu Chandra
Date Deposited:	10 Apr 2012 11:42
Last Modified:	10 Apr 2012 11:42
URI:	http://npl.csircentral.net/id/eprint/109

Actions (login required)

View Item