Analyzing indentation behavior of LaGaO3 single crystals using sharp indenters

In this work, the mechanical properties of (1 0 0) and (0 0 1) oriented LaGaO3 single crystals have been studied using sharp indenters. Vickers hardness values for both the (1 0 0) and (0 0 1) samples were found to be in the same range (∼8 GPa). The values for the indentation fracture toughness (KR) from Vickers indentation on the (1 0 0) samples were determined to be 0.8 ± 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 (0 0 1) samples. These measurements led to estimates of 0.5 ± 0.1 and 1.3 ± 0.3 MPa m1/2 for the two different sets of cracks on the (0 0 1) samples. In situ nanoindentation inside the SEM using a cube-corner indenter has also been used for studying the indentation fracture response of these samples.