Anisotropic thermal expansion of indium

In order to resolve differences in the reported data on thermal expansion, the lattice parameters of pure indium have been redetermined as functions of temperature over the range 27° to 106°C. The work was done independently on two cameras with good agreement in the results. The principal coefficient of thermal expansion along the a and b directions of the tetragonal structure is found to be independent of temperature and equal to 60.5 × 10^-6 °C^-1. A negative coefficient, which increases in magnitude with temperature, is obtained for the expansion along the tetragonal axis. The results are compared with those from earlier reports and discussed in relation to the available data on the elastic behaviour of the metal.