Novel Single Layers of Holey Crystalline Strcutures of Hf8s12 With Diverse Magnetic States

Abstract

Motivated by recent experiments revealing the synthesizability of novel M 8 X 12 (where M=transition metal and X=S, Se, or Te) type holey structure transition metal chalcogenide crystals such as W8Se12, the structural, electronic and vibrational properties of the single layer Hf8S12 are investigated. Density functional theory (DFT) based total energy optimizations and dynamic stability analysis show that hafnium disulfide crystals with the known 1T phase are stabilized in the holey crystal structure represented by the chemical formula Hf8S12. While 1T-HfS2 crystals are nonmagnetic, holey Hf8S12 material exhibits 4 different magnetic states along with the ferromagnetic ground state. All these magnetic states display indirect or quasi-indirect narrow bandgap semiconducting behavior. Moreover, it is shown that the in-plane stiffness and Poisson ratio values of each possible magnetic phase of Hf8S12 has a distinctive angle dependency against applied strain. Its stable crystal structure and the magnetic diversity show that Hf8S12 can bean important candidate for magneto-mechanical applications.