A pressurized high-temperature Debye-Scherrer camera, and its use to determine the structures and coefficients of expansion of γ - and δ -manganese

A new, pressurized high-temperature Debye-Scherrer camera is described. The structures of γ- and δ-manganese are found to be face-centred cubic and body-centred cubic respectively. Accurate curves of lattice-spacing against temperature are given for both these phases, and also for the β-manganese phase, and the transition temperatures agree well with other determinations. The mean values of the linear coefficients of thermal expansion of the phases over their regions of stability, and the volume changes resulting from the transformations, are evaluated.