Abstract
Relaxor ferroelectrics PbMg1/3Nb2/3O3-PbTiO3single crystals exhibit outstanding electromechanical properties and are potential materials for sonar applications. Since the methods of obtaining large single crystals are very expensive, the low cost textured ceramics are a very good alternative. Poled (FC or RT) and unpoled PMN-29%PT (single crystals) and PMN-34.5%PT (textured ceramics, L= 0.9) were investigated. The Rayleigh lines and Raman modes were studied between 20 and 240°C. The temperature dependences of intensities, frequencies and FWHMs were used to better understand the phase transitions. Differences are evidenced for poled and unpoled materials in good agreements with the thermal expansion and dielectric results. Although NbO6 sublattice remains stable over the 20-240°C temperature range, a continuous softening of the TiO6 and step transitions of the Pb2+ sublattices are evidenced. Rayleigh wings intensity appears sensitive to the nanostructure rearrangement.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call