Coexistence of monoclinic and tetragonal phases in PMN-PT single crystal
  The purpose of the present work is to report studies on structural phase transition for PMN-xPT single crystal, with melt PbTiO3 composition around the MPB (x = 0.35 mol %), using infrared spectroscopy technique. The study was centered on monitoring the behavior of the stretching-(Nb-O), stretching-(Ti-O) and stretching-(Mg-O) stretching modes as a function of temperature. Singularities observed between 198 and 300 K suggested a possible coexistence between the monoclinic and tetragonal phases, not revealed by others techniques, for PMN-PT composition studied near MPB. 
E.B. Araujo, C.A. Guarany, K. Yukimitu, J.C.S. Moraes and A.C.   Hernandes