Electronic topological transition in AuX2 (X = In, Ga and Al) compounds at high pressures

We present accurate x-ray diffraction data at high pressures for AuIn 2, AuGa 2 and AuAl 2 , obtained using a diamond anvil cell with the ELETTRA synchrotron source. The resulting P – V data obtained from the d -values were used to get the universal equation of state (UEOS), which is compared with theoretical estimates. Deviation from linearity is evident in the UEOS curves of AuIn 2 and AuGa 2 , thus verifying that some of the observed anomalies in these systems below 5 GPa are due to electronic topological transitions.