Synthesis and crystal structure of Cs3ZnBr5

The compound Cs 3 ZnBr 5 was synthesized from cesium and zinc bromides. The single crystals were grown by the Bridgman method. The structure of Cs 3 ZnBr 5 was studied. The compound crystallizes in the tetragonal system with the unit cell parameters: a = b = 9.633(2) Å, c = 15.141(5) Å, V = 1404.8(6) Å 3 , Z = 4, space group I 4/ mcm ; ρ calcd = 4.083 g/cm 3 , ρ exp = 4.074 ± 0.001 g/cm 3 . The compound Cs 3 ZnBr 5 is not hygroscopic and congruently melts at 530°C; it is transparent at 2.5 to 25 μm. The refractive indices are N p = 1.682, N g = 1.686. The microhardness is 560 MPa.