Shubnikov-de haas effect in thin films of cadmium arsenide

Hall effect and transverse magnetoresistance measurements on a thin well-oriented polycrystalline film of n-type cadmium arsenide and transverse magnetoresistance measurements on a single crystal of n-type cadmium arsenide were carried out at temperatures of 4.2 and 77 K in pulsed magnetic fields B of up to 30 T. Shubnikov-de Haas oscillations of the Hall voltage and resistivity in the thin film and of the resistivity in the single crystal were observed as the ,agnetic field varied. For both samples the periods of the oscillations calculated using the relation ζ 0 = a h ̵ ω or measured from the slope 1 B = f(a or n) are in good agreement with those calculated from Hall coefficient measurements. The linearity of the Hall voltage and of the transverse magnetoresistance were investigated at 4.2 and 77 K for B up to 30 T for different sample currents ( i x = 1.12–100 mA (d.c.) and i x = 1 mA (a.c.)). Both the Hall voltage and the transverse magnetoresistance were rectilinear functions of the magnetic field up to 25 T for i x = 1 mA (a.c. or d.c.) using the relations U H ≈ B and ϱ B ≈ μ B (μ B ⪢ 1). The results obtained for the thin film—from the Hall voltage and from the transverse magnetoresistance—are almost identical and compare well with the data obtained for the single crystal. They show that a good stoichiometric structure of a thin film of cadmium arsenide can be obtained by thermal vacuum evaporation.