Prasad, R. and Singh, M. P. and Siwach, P. K. and Fournier, P. and Singh, H. K. (2008) Anomalous insulator-metal transition and weak ferromagnetism in Nd0.37Sr0.63MnO3 thin films. EPL (Europhysics Letters), 84 (2). 27003-1-27003-5. ISSN 0295-5075

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Abstract

We report thickness-dependent magnetic and transport properties at the boundary separating A- and C-type antiferromagnetic phases in films of the overdoped manganite Nd0.37Sr0.63MnO3. The thin films are prepared by DC magnetron sputtering on single-crystal LaAlO3 substrates. All films, 5–120 nm in thickness, show a paramagnetic-ferromagnetic (PM-FM) transition. The small value of magnetization (≤0.45 μB/Mn) is suggestive of the weak nature of the FM correlations that is different from the prototype PM-FM transition due to double exchange (DE). At lower film thicknesses, such as 5 and 25 nm, zero-field resistivity shows an insulator-like behavior. An insulator-metal (IM) transition is observed at higher film thicknesses (≥60 nm). The magnetic-field independence of the observed IM transition (TIM~125 K) distinguishes it from the same observed in prototype manganites (x~0.2–0.4) and explained by DE. For the thinnest films, a CMR effect as large as MR~85% is observed in the low-temperature regime. The observed phenomena can be explained in terms of orbital-fluctuation–induced phase separation.

Item Type:	Article
Uncontrolled Keywords:	Copyright for this article belongs to M/s Institute of Physics.
Subjects:	Physics
Divisions:	UNSPECIFIED
Depositing User:	Ms Neetu Chandra
Date Deposited:	10 Jan 2013 11:38
Last Modified:	10 Jan 2013 11:38
URI:	http://npl.csircentral.net/id/eprint/944

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