Structural transformation in LaGa2under high pressure

High-pressure structural stability studies have been carried out on LaGa2 (AlB2 type structure at NTP, space group P6/mmm) up to a pressure of ∼60 GPa. A structural phase transition was initiated at a pressure of ∼12 GPa and a complete transformation to the daughter phase occurred at ∼28 GPa. The high-pressure phase was identified to be orthorhombic with lattice parameters: a = 12.79, b = 5.09 and c = 5.28 Å at 60 GPa. The bulk modulus B 0 and its derivative for the parent phase were found to be 100 ± 16 GPa and 5 ± 4, respectively. The bulk modulus Br and its derivative for the high-pressure phase were found to be 166 ± 18 GPa and 17 ± 4, respectively.