Growth, Structural and Micro hardness studies of KSbF4 and K2SbF5 crystals

C. Besky Job, R. Shabu, S. Paulraj

Interest in Potassium Fluoro Antimonate crystals has been increased for the last four decades due its superionic conduction and its unusual electro-optic properties. Potassium tetra fluoro antimonate (KSbF₄) and Potassium penta fluoro antimonite (K₂SbF₅) crystals have been grown by slow evaporation method. KSbF₄ crystallizes into orthorhombic structure with a space group Pmmn. K₂SbF₅ belongs to orthorhombic crystal system with a space group Cmcm.  Micro indentation analysis on these crystals indicates that they are moderately softer substances. Both crystals revealed reverse indentation size effect (RISE). Variation of stiffness constant with load has been discussed. Yield strength for KSbF₄ and K₂SbF₅ crystals have been found out as 16.72 and 16.941 MPa respectively.