The complexity of structural phase transitions in Pb(Hf0.92Sn0.08)O3 single crystals

Pb(Hf1-xSnx)O-3 single crystals with x = 0.08 were characterized using single-crystal X-ray diffraction and Raman scattering, in a wide temperature range. The information concerning the structure of two intermediate phases (IMs), situated between low-temperature antiferroelectric A1 and high-temperature paraelectric PE phases, was obtained. The lower temperature IM, A2, is characterized by incommensurate displacive modulations in the Pb sublattice. The higher temperature IM, is characterized by tilting of oxygen octahedra, and serious disorder coming from lead ions represented by X-ray diffuse scattering. Optical phonons and phase transitions in Pb(Hf1-xSnx)O-3 single crystals were investigated by temperature-dependent Raman spectra. It was found that several soft modes control the phase transition between two antiferroelectric phases indicating its displacive character, whereas, in the paraelectric phase, both soft modes and Rayleigh scattering were observed.

Automated summary

Pb(Hf1-xSnx)O-3 single crystals with x = 0.08 were characterized using single-crystal X-ray diffraction and Raman scattering. Information about the structure of two intermediate phases and the optical phonons in the crystals were obtained. The study also revealed the control of soft modes on phase transitions in antiferroelectric phases.