Pressure dependence of instabilities in perovskite PbZrO3

✍ Scribed by E. Cockayne; K.M. Rabe

• Book ID: 104152181
• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 78 KB
• Volume: 61
• Category: Article
• ISSN: 0022-3697
• DOI: 10.1016/s0022-3697(99)00298-x

✦ Synopsis

We have computed the frequencies of selected normal modes in perovskite PbZrO 3 (PZ) as a function of lattice parameter using local density-functional theory variational linear response. The harmonic instabilities of the perovskite structure which freeze in to give the orthorhombic antiferroelectric (AFE) phase in PZ and the low-temperature rhombohedral ferroelectric (FE) phase in PbZr 1Ϫx Ti x O 3 (PZT) all become more unstable under pressure. The most unstable AFE S 3 mode destabilizes more rapidly under pressure than the unstable zone center polar mode. This provides an explanation for the observed FE-AFE transition in (modified) Zr-rich PZT under applied pressure.