Hydrostatic pressure dependences of elastic constants and vibrational anharmonicity of uranium nitride

摘要: Measurements of the effect hydrostatic pressure on ultrasonic wave velocities have been used to determine derivatives elastic stiffness uranium nitride at room temperature.∂C44/∂P, and hence Gruneisen parameter for transverse mode propagating down an 〈001〉 axis, is negative; however, this softening not anomalous rocksalt structure crystals. The gammas acoustic modes obtained in long wavelength limit a pronounced anisotropy which accrues largely from presence or absence contributions vibration nearest-neighbour repulsive forces. compression calculated Murnaghan equation state much smaller than those alkali halides IV–VI compounds because compound stiffer.