Elasticity of Dense Metal–Organic Framework Compounds

Abstract

We present for the first time the experimentally derived complete elastic stiffness tensors of orthorhombic metal guanidinium formates, ([C(NH 2 ) 3 ]-[M 2+ (HCOO) 3 ], MGFs), with M 2+ = Zn 2+ , Mn 2+ , and Cu 2+ which are structurally related to (ABX 3 )-perovskites using ultrasound techniques, Brillouin spectroscopy, and thermal diffuse scattering. Density functional theory calculations were also performed to calculate the elastic tensor of orthorhombic MGFs and extended to the study of trigonal MGFs with M 2+ = Ca 2+ and Cd 2+ . All MGFs studied here are very compressible, with bulk moduli ranging from 20 to 30 GPa. The MGFs possess a significant anisotropy in their elastic properties, which is extremely large, especially in the case of CdGF and CaGF.