Electrical Resistance of Binary Ordered Alloys with HCP Structure in the Presence of Impurity Atoms or Thermal Vacancies

The electrical resistance of alloy is determined by the conduction electron scattering in the crystal lattice when the potential field of the crystal shows a broken periodicity [1–5]. This scattering is characterized by probability of the electron transition between different equilibrium states.The calculation of residual resistance has been performed in present paper for the cases when in disordered state the positions of lattice sites form the Bravais lattice and each lattice site is the centre of crystal symmetry. But the phenomenon of ordering is observed also in a series of alloys with crystal lattices of more low symmetry, for example alloys with hexagonal close-packed lattice. Moreover the impurity atoms and thermal vacancies have effect on electrical resistance. So the consideration of these cases is of physical interest.Below is given in the context of zone theory the theoretical investigation and the computer calculation of residual resistance at first for binary ordered alloys with h.c.p. lattice of AB and AB3 composition [6] with comparison of theoretical results with experimental data for MgCd₃ and Mg₃Cd alloys [7] and then the resistance of these alloys containing impurity atoms or thermal vacancies [7, 8].The calculations have been performed in some simplifying assumptions. The correlation between substitution of lattice sites by atoms of different sorts is not taken into consideration. The crystal lattice is assumed to be geometrically ideal, i.e. it is free from any geometric distortions in overall concentration range of alloy. The differences in energies for interaction between conduction electrons and lattice ions of A, B, C kind are considered to be small values.