A high-pressure study of thallium

High-pressure experiments on metallic thallium have been carried out using a diamond-anvil cell for pressures up to 32 GPa. A hexagonal close packed → face-centred cubic (f.c.c.) phase change takes place around 4 GPa. Fitting of the experimental data to the Murnaghan and Birch equations of state has been used to obtain values for the bulk moduli and their pressure derivatives for the two phases. Extrapolation of the high-pressure data for the f.c.c. phase to low pressure has been used to obtain an estimate of the pressure to about 0.23 GPa in nanosized metastable f.c.c. thallium inclusions formed in aluminium by ion implantation.