Mechanical properties of Li2MoO4 single crystals

Mechanical properties of lithium molybdate single crystals, Li2MoO4, are studied from room temperature to 650 degrees C. Density functional theory calculations gave the seven elastic constants of the rhombohedral crystal at 0 K. Brillouin light scattering experiments delivered comparable values at room temperature, and measurements up to 650 degrees C show a linear decrease in the constants with temperature. Nano-indentation results were typical of a brittle material with a low Young modulus and allowed deriving Young's moduli, for c (63 GPa) and m (48 GPa) faces, in agreement with those computed from measured elastic constants. Compressive rupture tests were performed. At 650 degrees C, the rupture stress was in the range 2-7.5 MPa. No clear evidence of a plastic regime was observed before cracking, even at temperatures close to the melting point. Published under an exclusive license by AIP Publishing.