Analyzing indentation behavior of LaGaO3 single crystals using sharp indenters

The mechanical properties of (100) and (001) oriented LaGaO3 single crystals were studied using sharp indenters. Vickers hardness values for both the (100) and (001) samples were in the same range (about 8 GPa). The values for the indentation fracture toughness from Vickers indentation on the (100) samples were determined to be 0.8 plus or minus 0.2 MPa.m1/2. Different crack lengths, implying a strong anisotropy in the indentation fracture toughness values, were observed in the two mutually perpendicular directions in the indentations on the (001) samples. These measurements led to estimates of 0.5 plus or minus 0.1 and 1.3 plus or minus 0.3 MPa.m1/2 for the two different sets of cracks on the (001) samples. In-situ nanoindentation inside the SEM chamber using a cube-corner indenter was also used to study the indentation fracture response of these samples. 39 refs.