Mandal, P and Choudhury, Pranab and Ghosh, B (2006) Electronic transport in ferroelectric-ferromagnetic composites La-5/8(Ba,Ca)(3/8)MnO3 : LuMnO3. Physical Review B, 74 (9). ISSN 1098-0121

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Abstract

An almost complete immiscibility between metallic ferromagnet La5/8Ba3/8MnO3 or La5/8Ca3/8MnO3 and insulating ferroelectric LuMnO3 has been established from structural, magnetic, and transport studies. Both (x)La5/8Ba3/8MnO3:(1-x)LuMnO3 and (x)La5/8Ca3/8MnO3:(1-x)LuMnO3 show a metal-insulator transition below a critical volume fraction x(vc) of the metallic component. Over the entire range of x > x(vc), electronic conduction follows a classical percolation model. The conductivity scaling exponent t is the same as that of the universal value (=2) for the three-dimensional (3D) system; x(vc) is also close to the theoretical prediction for the 3D continuum model. For x < x(vc), the transport phenomenon is dominated by the insulating LuMnO3. The temperature dependence of both resistivity and thermopower for 0 <= x < x(vc) shows that the conduction is due to the thermal activation of charge carriers with a band gap similar to 0.5 eV.

Item Type:	Article
Uncontrolled Keywords:	CONDUCTIVITY EXPONENT; PRECISE DETERMINATION; PERCOLATION; TRANSITIONS; MANGANITES; MIXTURES; YMNO3; FILMS
Subjects:	General
Divisions:	UNSPECIFIED
Depositing User:	Mrs Chandana Patra
Date Deposited:	28 Dec 2011 05:29
Last Modified:	28 Dec 2011 05:32
URI:	http://cgcri.csircentral.net/id/eprint/43

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