Reversible amorphization and structural memory effect in clathrasil dodecasil-3c

Abstract

The mechanism for the novel structural memory effect, where a crystalline solid compressed to an disordered phase is able to revert back to the original crystal structure upon the release of the pressure, is investigated using clathrasil dodecasil as a model system. It was found, through experiments and theoretical molecular dynamics calculations, that the presence of undeformable units, such as the guests, are essential for the reversible process. The transformation of the clathrasil to a high density disordered structure at high pressure is due to a mechanical instability. In the absence of atomic diffusive motions, when the pressure is relieved the encaged guests act as templates and redirect the atoms collapsed around them back into the original structure.