Structural transitions in (La,Ln)2CuO4 and La2(Cu,Ni)O4 systems

Singh, KK and Ganguly, P and Rao, CNR (1982) Structural transitions in (La,Ln)2CuO4 and La2(Cu,Ni)O4 systems. In: Materials Research Bulletin, 17 (4). pp. 493-500.

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Abstract

Solid solutions of the formula La2−xLnxCuO4 (Ln = Pr, Nd) possess the orthorhombic structure of La2CuO4 for small values of x and transform to the tetragonal Nd2CuO4 structure at a critical value of x. At the critical composition, there is an abrupt change in specific volume as well as the Image ratio. The material exhibits temperature-independent electrical resistivity below the critical value x and semiconducting behaviour above it. The specific volume and Image ratio smoothly decrease with increase in x in the La2Cu1−xNixO4 system, although the solid solution possess the tetragonal K2NiF4 structure when x>0.1. Compositions with x>0.1 exhibit a gradual semiconductor metal transition similar to that of La2NiO4, the transition temperature decreasing with increasing

Item Type:	Journal Article
Publication:	Materials Research Bulletin
Publisher:	Elsevier Science.
Additional Information:	Copyright of this article belongs to Elsevier Publisher.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	22 Dec 2009 06:08
Last Modified:	19 Sep 2010 05:45
URI:	http://eprints.iisc.ac.in/id/eprint/23307

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