Solid solutions of the Pb^II(M_1−xM_x′)^IVO₃ (M, M′=Ti, V and Cr) perovskites, synthesized under high pressure and high temperature

Abstract

The structural characteristics of Pb(M_1−x M)O₃ solid solutions, with M, M′=Ti, V and Cr, have been investigated by powder X-ray diffraction. The specimens studied were synthesized under high pressure and high temperature in a ‘belt-type’ apparatus. The analogy between polymorphic, compared with the PbTiO₃ (tetragonal↔cubic phase transition), and morphotropic transformation in these systems is sufficiently close so as to be able to use the Birch–Murnaghan equation of state of PbTiO₃ and relate it to the internal (or the so-called ‘chemical’) pressure generated by the substitution of vanadium or chromium along the different solid solutions.

Keywords:

• perovskite
• solid solution
• chemical and external pressure
• equation of state

Acknowledgements

Samples were obtained at LABCOAP (http://www.ucm.es/info/labcoap/index.htm) with the help of Dr Jose Manuel Gallardo Amores. A.M.A.-L. acknowledges CONACYT for a PhD grant. This work was funded by CICYT (Project MAT2007-64007), Comunidad Autónoma de Madrid (Program MATERYENER, PRICYT S-0505/PPQ-0093,2006) and Fundación Areces (Ayudas 2004): ‘Física de bajas temperaturas’.