Low Temperature Physics: 39, 84 (2013); https://doi.org/10.1063/1.4775749 (5 pages)
Pseudogap state and strong scattering of current carriers by local spin moments as the mechanisms of appearance of semiconductor properties of almost stoichiometrical iron-vanadium-aluminium alloys
A.T. Lonchakov, V.V. Marchenkov, V.I. Okulov, and K.A. Okulova
Institute of Metal Physics , S. Kovalevskoyi st. 18, Ekaterinburg 620990, Russia
Received November 6, 2012
New experimental data are obtained which substantiate the physical nature of semiconductor properties of Fe2–xV1+x Al alloys with almost stoichiometrical composition (x = 0). We investigated low temperature thermoelectric power of two alloys of characteristic compositions: one alloy, enriched with vanadium, exhibited a pseudogap in the density of states of electrons with Fermi energy and the other one vanadium depleted, more strong influence of the scattering of electrons by localized spins is revealed. The experimental temperature dependences of thermoelectric power at low temperatures displayed characterristic anomalies that were observed for the first time and which in line with our analysis conform to the manifestations the effects above. Using the existing theories, the anomalous contributions of the both effects (types) were interpreted, the parameters, characterizing them have determined and the specific features of their presence in V-depleted and V-enriched alloys have also established. The data for thermoelectric power in magnetic field were obtained. It is found that thermoelectric power decreases considerably with increasing field intensity, confirming the key role of the mechanism of current carrier scattering by localized moments.
PACS: 71.20.Be Transition metals and alloys;
Key words: low temperature thermoelectric power, iron-vanadium-aluminium alloys, density of states of electrons.