Tb₃Sn₇: polymorphism and crystal structure of high-temperature modification

The temperatures of non-variant transformations in the tin-rich side of the Tb–Sn binary system were refined using differential scanning calorimetry. The crystal structure of βTb₃Sn₇ was determined for the first time from single-crystal diffraction data. The structures of α- and β-modifications were analysed and a possible mechanism of polymorphic transformation proposed.