A method for crystallizing an amorphous multicomponent ionic compound comprises applying an external stimulus to a layer of an amorphous multicomponent ionic compound, the layer in contact with an amorphous surface of a deposition substrate at a first interface and optionally, the layer in contact with a crystalline surface at a second interface, wherein the external stimulus induces an amorphous-to-crystalline phase transformation, thereby crystallizing the layer to provide a crystalline multicomponent ionic compound, wherein the external stimulus and the crystallization are carried out at a temperature below the melting temperature of the amorphous multicomponent ionic compound. If the layer is in contact with the crystalline surface at the second interface, the temperature is further selected to achieve crystallization from the crystalline surface via solid phase epitaxial (SPE) growth without nucleation.