Thermal conductivity in A₃B intermetallic compounds based on iron and nickel

Thermal conductivity of A₃B intermetallic compounds, where A denotes iron or nickel and B denotes group IIIb or IVb elements, is investigated by a laser-flash method. Among six kinds of L1₂, compounds, the largest thermal conductivity observed is 32.8 W m^-1 K^-1 of Ni₃Ga. In Fe₃Ga and Fe₃Ge, three polymorphs, i.e. L1₂, D0₁₉ and D0₃, can be achieved by performing a suitable heat treatment. Thermal conductivity of the D0₁₉ phase is quite close to that of the L1₂ phase, while the D0₃ phase shows smaller values. In most A₃B compounds, the measured thermal conductivities tend to decrease as the position of constituent B becomes horizontally more distant from that of constituent A in the periodic table.