Elastic and antiferromagnetic anomalies in Pr _0.48 Ca _0.52 MnO ₃ as determined by resonant ultrasonic spectroscopy

Salje, E. K. H. and Carpenter, M. A. (2011) Elastic and antiferromagnetic anomalies in Pr _0.48 Ca _0.52 MnO ₃ as determined by resonant ultrasonic spectroscopy. Journal of Physics: Condensed Matter, 23 (24). p. 245401. DOI 10.1088/0953-8984/23/24/245401

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Abstract

High pressure measurements of the ferroelastic phase transition of SrTiO3 (Guennou et al 2010 Phys. Rev. B 81 054115) showed a linear pressure dependence of the transition temperature between the cubic and tetragonal phase. Furthermore, the pressure induced transition becomes second order while the temperature dependent transition is near a tricritical point. The phase transition mechanism is characterized by the elongation and tilt of the TiO6 octahedra in the tetragonal phase, which leads to strongly nonlinear couplings between the structural order parameter, the volume strain and the applied pressure. The phase diagram is derived from the Clausius–Clapeyron relationship and is directly related to a pressure dependent Landau potential. The nonlinearities of the pressure dependent strains lead to an increase of the fourth order Landau coefficient with increasing pressure and, hence, to a tricritical–second order crossover. This behaviour is reminiscent of the doping related crossover in isostructural KMnF3.

Item Type:	Article
Uncontrolled Keywords:	2011AREP; IA63;
Subjects:	03 - Mineral Sciences
Divisions:	03 - Mineral Sciences
Journal or Publication Title:	Journal of Physics: Condensed Matter
Volume:	23
Page Range:	p. 245401
Identification Number:	10.1088/0953-8984/23/24/245401
Depositing User:	Sarah Humbert
Date Deposited:	12 Aug 2011 16:09
Last Modified:	23 Jul 2013 10:02
URI:	http://eprints.esc.cam.ac.uk/id/eprint/2165

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