Electronic topological transition in AuX<SUB>2</SUB> (X = In, Ga and Al) compounds at high pressures

We present accurate x-ray diffraction data at high pressures for AuIn2, AuGa2 and AuAl2, 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 AuIn2 and AuGa2, thus verifying that some of the observed anomalies in these systems below 5 GPa are due to electronic topological transitions