The features of structural, energy state and electrokinetic characteristics were investigated for Hf1‑xTmxNiSn solid solution in the range: T = 80 - 400 K, x = 0 - 0.40. It was confirmed partly disorder crystal structure of HfNiSn compound as a result of occupation in the 4a crystallographic site of Hf (5d26s2) atoms by Ni (3d84s2) ones up to ~ 1 % that generates in the crystal structural defects of donor nature. It was shown that introduction of Tm atoms ordered crystal structure (“healing” of structural defects). It was established mechanisms of simultaneous generation of structural defects as acceptors by substitution of Hf (5d26s2) by Tm (4f135d06s2) atoms, and the donor nature defects as a result of the appearance of vacancies in the Sn (4b) atoms sites, which determines the mechanisms of conductivity for Hf1-xTmxNiSn.

Дослідження структурних, енергетичних та кінетичних характеристик напівпровідників RNiSb (R = Gd, Lu)1 Львівський національний університет ім. І.Франка, вул.

Peculiarities of the structural, electrokinetic, energetic, and magnetic characteristics of Er1-xZrxNiSb semiconductive solid solution, х=0–0.10, were studied. It was suggested that when Zr (4d25s2) atoms were introduced into the structure of the ErNiSb half-Heusler phase by substitution of Er (5d06s2) atoms in 4a position, Zr atoms can also simultaneously occupy the 4c position of Ni (3d84s2) atoms. As a result, in Er1-xZrxNiSb semiconductor, the structural defects of donor nature in position 4a and ones of acceptor nature in position 4c were generated simultaneously. In this case, in the band gap of Er1-xZrxNiSb, the energy states of impurity donor  and acceptor  bands (donor-acceptor pairs) appear and determine the electrical conductivity mechanism of the semiconductor.

The effect of doping of the TiCoSb compound (MgAgAs structure type) by Mo atoms on the features of the structural characteristics and behavior of the electrokinetic, energetic and magnetic properties of the Ti1-xMoxCoSb semiconducting solid solution (х = 0 - 0.06) in the temperature interval 80 - 400 K was studied. It was shown that including of Mo atoms (rМо= 0.140 nm) in the ToCoSb structure by substitution of Ti atoms (rТі= 0.146 нм) in 4a position is accompanied with non-monotonous variation of the lattice parameter values а(х), indicating unpredictable structural changes. Based on analysis of the variation of the electric resistivity values, thermopower coefficient, magnetic susceptibility and energetic characteristics, it was concluded that simultaneous generation in the crystal of the structural defects of the donor and acceptor nature (donor-acceptor pairs), which generate corresponding energy levels in the band gap of semiconductor and determine its electrical conductivity.

Features of structural, electrokinetic, and energy state characteristics of ZrNiSn1-xGax semiconductive solid solution were investigated in the temperature ranges Т = 80 - 400 K and х = 0 - 0.15. Disorder of crystal structure for n-ZrNiSn compound as a result of occupation of Zr (4d25s2) atoms in 4a sites by Ni (3d84s2) ones up to ~ 1 % was confirmed. It generated donor levels band ɛD1 in the band gap. It was shown that introduction of Ga (4s24p1) atoms by means of substitution of Sn (5s25p2) ones ordered crystal structure. In this case acceptor defects were generated in 4b sites and it created extended acceptor impurity band ɛА. It was suggested that with generation of acceptor structural defects the vacancies in the Sn (4b) atomic sites simultaneously generated donor defects and formed deep donor band ɛD2 (donor-acceptor pair took place).