Structure of liquid GaSb under pressure

The structure of liquid GaSb has been investigated up to 19.6 GPa by an energy-dispersive X-ray diffraction method in conjunction with a synchrotron radiation source and a multi-anvil high-pressure apparatus. The structure factors, S(Q), and the pair-distribution functions, g(r), at high pressures show that the local structure of liquid GaSb does not contract uniformly. From the comparison between the position of the first peak in g(r) and the interatomic distances calculated for the structures of high-pressure polymorphs of the group IV elements, it is found that the local structure of the liquid changes from a beta-tin-like structure into a body-centered-tetragonal-like structure with increasing pressure. Corresponding to the shift of the first peak, the coordination number increases. These results show that liquid GaSb contracts by changing the local structure under pressure.