Sequence of phase transitions in PbHfO.

Kupriyanov, M.; Petrovich, E.; Dutova, E.; Kabirov, Yu.

The temperature changes in the PbHfO structure in the temperature range of 20 < t < 400°C have been studied by X-ray powder diffraction. The sequence of phase changes with an increase in temperature was found to be as follows: orthorhombic phase Pbam (O1), orthorhombic phase C2 mm (O2), tetragonal phase P4 mm (T), and cubic phase Pm3 m (C). The C2 mm and P4 mm phases are ferroelectric, which is confirmed by measuring the dependences ɛ( t). The similarity of the transition pattern obtained with the known transition sequences for ferroelectric (barium titanate, potassium niobate, and lead titanate) and antiferroelectric (lead zirconate) oxides is analyzed.

PHASE transitions; TEMPERATURE effect; X-ray diffraction; FERROELECTRIC crystals; BARIUM titanate; ANTIFERROELECTRIC liquid crystals; NIOBATES

Crystallography Reports, 2012, Vol 57, Issue 2, p205

1063-7745

Academic Journal

10.1134/S1063774512020125