CORRELATION BETWEEN STRUCTURAL STABILITY AND ELECTRONIC STRUCTURE OF UGa3 UP TO 30 GPa

Abstract

High-pressure angle-dispersive X-ray diffraction experiments were performed on UGa 3 up to 30 GPa within a diamond-anvil cell. UGa 3 remains in its cubic AuCu 3 type structure up to the maximum pressure studied and does not show any structural phase transition. To understand the structural stability of UGa 3, band structure calculations were performed as a function of reduced volume using the full-potential linear augmented plane wave (FP-LAPW) method. The results show that the Fermi level coincides with a deep valley in the density of states (DOS) curve in the antiferromagnetic state, whereas it lies near a valley (towards the bonding side) in the nonmagnetic state. At high pressures, the DOS near EF does not show much variation in both the cases. The experimental and theoretical equation of state, bulk modulus, and its pressure derivative values are also reported. The pressure dependence of magnetic moment shows a linear decrease at the rate of dμ/dP = -0.027 μ B / GPa .