Mechanical behaviour and fracture mechanism of flux grown holmium orthoferrite single crystals Original Research Article

Results of indentation induced microhardness and fracture studies on (110) and (001) planes of flux grown HoFeO3 single crystals using a Vickerʹs hardness tester, in the load range of 10–100 g are presented. The variation of microhardness with load is found to be non-linear and is explained by using Hays and Kendallʹs law. The hardness results and the indentation-induced cracking yields the values of the yield strength, fracture toughness and brittleness index for (110) and (001) planes of HoFeO3 crystals. Transition from Palmqvist to median crack systems takes place at higher loads for (110) plane of the crystal whereas (001) plane is characterized by Palmqvist cracks only.