Experimental evidence for an intermediate phase in the multiferroic YMnO3
Résumé
We have carried out high temperature synchrotron x-ray experiments, differential scanning calorimetry and thermomechanical analysis on a single-crystal of YMnO3 grown by the Floating Zone Technique. These experiments show two anomalies at about 1100K and 1350K demonstrating the existence of an intermediate phase between the ferroelectric P63cm structure and the high temperature centrosymmetric phase with P63/mmc symmetry. This work identifies for the first time the different high temperature phase transitions in YMnO3.