Magnetic in homogeneity and Griffiths phase in Bisubstituted La0.65�xBixCa0.35MnO3 manganites

Manjunatha, S O and Rao, Ashok and Poornesh, P and Lin, W J and Kuo, Y K (2016) Magnetic in homogeneity and Griffiths phase in Bisubstituted La0.65�xBixCa0.35MnO3 manganites. Physica B, 498 (1). pp. 82-91. ISSN 0921-4526

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Abstract

In the present communication, we report the effect of Bi substitutionon structural,magneto-transport, magnetic and thermal properties of La0.65�xBixCa0.35MnO3 (0rxr0.2) compounds.Rietveldrefined XRD patterns confirm that all the sample sare single phase and crystallize inrhombohedralsymmetrywith R- 3C space group. It was observed from electrical and magnetic studies that with increasing Bi content both the metal-insulat or transition temperature(TMI) and ferromagnetic–paramagnetic (FM–PM) transition temperature(TC) shift towards lower temperatures. Deviation of the temperature dependence of inverse susceptibility curves from the Curie–WeisslawsuggeststheexistenceofGriffiths-like phase.Theelec- trical resistivitydatawereanalyzedbyutilizingvarioustheoreticalmodels.Itisrevealedthattheelec- tron–electron scatteringisdominatinginthemetallicregion,whiletheinsulatingregioniswell-de- scribed bythepolaronhoppingmodel.Analysisofthermoelectricpowerdatafurtherrevealsthatthe small polaronhopping(SPH)mechanismisoperativeinthehigh-temperatureinsulatingregime.The entropychangeassociatedwiththeFM–PM transitionisfoundtodecreasewithincreasing x, which is presumablyduetotheincreaseinmagneticinhomogeneitywithincreasingBicontent

Item Type: Article
Uncontrolled Keywords: Manganites; Griffiths phase; Thermoelectric power
Subjects: Engineering > MIT Manipal > Physics
Depositing User: MIT Library
Date Deposited: 21 Sep 2016 09:01
Last Modified: 21 Sep 2016 09:01
URI: http://eprints.manipal.edu/id/eprint/146997

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