Annealing Behavior of Twin Domains in YBa2Cu3Ox Crystals

Abstract
The behavior of YBa2Cu3O x crystals upon annealing was investigated by a polarizing microscope. Gradual transformation between the orthorhombic and tetragonal phases was observed in situ on heating and on cooling in oxygen atmosphere. An obvious change was recognized between twin domain structures before and after annealing. It is indicated that there is a possibility of reducing the number of twin domains in the crystal.