Monoclinic-orthorhombic transition in K₂ZnBr₄ and Rb₂ZnI₄

Abstract

The first-order transition from the monoclinic α-phase to the orthorhombic β-phase in K₂ZnBr₄ and Rb₂ZnI₄ is investigated by X-ray diffraction. The structure of β-phase is confirmed to be isostructural with disordered β-K₂SO₄. Although structures of α ⁻ and β-phases are different so much with each other, the transformation proceeds without cracking or deforming the crystal.