Ni-Pb-Te phase equilibria and interfacial reactions in Ni/PbTe couples

•Reaction zone thickness is 120 μm in the Ni/PbTe couples reacted at 650℃.•The Ni/PbTe reaction path at 650℃ is Ni/β-Ni3Te2+Liquid (I)/Liquid (I)/PbTe.•No interfacial reactions in the Ni/PbTe couple reacted at 500℃ and 400℃ for a month.•Ni is the dominating diffusion species in the Ni/PbTe couples.•Liquid originating from Pb in Ni-Pb-Te at 650℃ has a peculiar deep and narrow shape.