Experimental evidence for an intermediate phase in the multiferroic YMnO₃

Abstract

We have studied YMnO 3 by high-temperature synchrotron x-ray powder diffraction, and have carried out differential thermal analysis and dilatometry on a single crystal sample. These experiments show two phase transitions at about 1100 K and 1350 K, respectively. This demonstrates the existence of an intermediate phase between the room temperature ferroelectric and the hightemperature centrosymmetric phase. This study identifies for the first time the different high-temperature phase transitions in YMnO 3 .