The characterrization of high temperature solution-grown crystals of Pb(Fe1/2Nb1/2)O3

摘要: Polarization microscope studies on single crystal samples of Pb(Fe1/2Nb1/2)O3 (PFN) have been made. Thin platelets (<60 μ) show large, homogeneous ferroelectrics domains, and optical characterization shows that PFN is trigonal at room temperature optically negative. Birefringence measurements between 4.2 400 K reveal the transition to cubic structure takes place 383 K, in accordance with earlier work, but they also locate a previously undetected structural modification 354 accompanied simultaneously by reorientation index ellipsoid; both transitions manifest themselves endothermic reactions heating DTA experiments. The new phase very likely monoclinic.