Transport Properties of n-ZrNiSn Single Crystals

Abstract

Electrical measurements have been carried out on n-type ZrNiSn single crystals. The observed temperature dependence of the Hall coefficient is explained in assuming the existence of an impurity band. The values of the activation energy of the shallow donors, their concentration and the concentration of the compensating acceptors were calculated. It is shown that the scattering due to acoustic phonons and ionized impurities is most important in the high and low temperature region, respectively. The value of the conduction band deformation potential is estimated.

High-temperature thermoelectric properties of Nb-doped MNiSn (M=Ti, Zr) half-Heusler compound

“…The properties can be estimated by the valence electron count (VEC) per formula. The halfHeusler compounds having 18 VEC, such as MNiSn [5][6][7][8][9][10][11][12], MCoSb (M = Ti, Zr, Hf) [13,14], HfPtSn [15], and LnPdSb (Ln: lanthanide) [16] exhibit unusual transport and optical property because of the band gap or pseudo-gap at the Fermi-level. Among these, MNiSn compounds have narrow indirect band gap and exhibit n-type semiconductor behavior.…”

“…Considerable efforts have been focused on reduction of the thermal conductivity. On the contrary, transport properties [12] at high temperature were scarcely reported for the compound. In this study, polycrystalline Nb-doped MNiSn (M = Ti, Zr) were synthesized and the thermoelectric properties were investigated.…”

Two-band conduction in electron-irradiated n-InSe single crystals

“…Modeling of the transport data An analysis of many experimental data, for example, in Refs. [24,25,[39][40][41][42][43][44], has been carried out within a two-band model as follows. Knowing the values of the Hall coefficient in the maximum, R max H , and in the range of impurity depletion, R sat H , the authors determined the concentration of the carriers in the main and impurity bands as a function of T. In so doing, it was assumed that the ratio of the mobilities in these bands did not change with temperature, which means the same scattering mechanism applies.…”

“…[42] was later used by many authors, for instance, in Refs. [24,25,43]. In the range near and below the Table 1 Electrical parameters of electron-irradiated InSe determined from Eqs.…”

Improved thermoelectric performance of (Zr0.3Hf0.7)NiSn half-Heusler compounds by Ta substitution

“…31 If an impurity band is present, VRH can originate from a smaller overlap of the electron wave functions of impurity atoms at low temperatures. 28 33 A more precise analysis of the VRH mechanism would require the acquisition of additional data points in the 1 K < T < 100 K temperature range, which is beyond the scope of this paper.…”