X-ray diffraction study of the structure and thermal parameters of the ternary Au–Ag–Pd alloys

In situ X-ray diffraction experiments were performed on six samples of the ternary Au–Ag–Pd alloys (with A1 structure) having different compositions using a Cu-target. The integrated intensity data obtained in the temperature range of 373–1200 K was utilized to determine the lattice parameters and the thermal parameters like Einstein's temperatures (ΘE), the mean-square amplitudes (u2¯(T)) and the coefficients of thermal expansion with a high accuracy. The lattice parameter showed a small negative deviation from the Vegard's rule. It is also found that the mean-square amplitudes are independent of the static displacements. The mean-square amplitudes of vibration and the linear thermal expansion follow the classical Grüneisen relationship in these alloys.