Ferroelastic domains and phase transitions in organic–inorganic hybrid perovskite CH3NH3PbBr3

Abstract
Polarized light microscopy reveals twin domains and symmetry of the phases in CH3NH3PbBr3 crystal; domain structure remains unresponsive to electric field but changes under external stress, confirming ferroelasticity while ruling out ferroelectricity.
Funding Information
  • Office of Naval Reactors (N00014-16-1-3106)
  • Natural Sciences and Engineering Research Council of Canada (RGPIN-2017-06915)