Transport Properties of ?-Fe1-xMnxSi2 Alloys

Abstract

The results of transport measurements on b-Fe 1Àx Mn x Si 2 alloys in the temperature range of 80 to 300 K are presented and explained assuming the existence of an impurity band. The values of the activation energies of the shallow and deep acceptors, their concentrations, the concentration of the compensating donors as well as the impurity band width were calculated.

Transport properties of β-FeSi2

“…22) and Mn (Ref. 25), yielding, however, less confident data (Table I). The values of ε 2 , N d , and N A2 were obtained for the β-FeSi 2 crystals grown from Zn solvent (see Table I).…”

“…1(a)] and films, 22) the single crystals, both Aldoped 23) and grown from Zn solvent [Fig. 1(b)], 24) as well as the β-Fe 1−x Mn x Si 2 alloys 25) show an exponential increase of the Hall coefficient R(T) with decreasing temperature T down to ∼50-170 K. In addition, it should be mentioned a wellpronounced maximum of R(T), which implies importance of the conductivity over a band formed by shallow impurity (or defect) levels. When the concentration of shallow impurities is increased, the magnitude of the Hall coefficient maximum 22) The numbers of the curves correspond to the sample numbers (Table I).…”

“…23) The value of ε = 244 meV, as well as the acceptor concentration N A = 3.3 × 10 19 cm −3 have been determined in a good agreement with the corresponding data obtained in β-Fe 1−x Mn x Si 2 . 25,34) 3.2 N-type β-FeSi 2 All n-type β-FeSi 2 single crystals grown by chemical vapor transport (CVT), both undoped and differently doped, show the nonlinear magnetic field dependence 36,43,44) and hysteresis 36,45) of the Hall voltage. The nonlinearity is strongly pronounced at low temperatures and is observed even at room temperature (RT).…”