Influence of antimony dopant in some physical properties of MnBi1-xSbx thin films

Compositional dependencies of the optical and electrical properties of as-deposited MnBi1-xSbx films, prepared by thermal evaporation, have been studied. Few measurements of the thermoelectric power and electrical resistivity of MnBiSb thin films have been performed previously. The thermoelectric power showed a negative sign for all thin films. rho(T) decreases monotonically with the temperature for all samples, indicating semiconductor behavior. The absorbance A (lambda) and reflectance R (lambda) of different doping (MnBi1-xSbx) thin films have been studied in the wavelength range 400-1500 nm. MnBi1-xSbx films with a high proportion of Sb can be used as adsorbents. The absorption value increases with increasing wavelength and then decreases again. Blue shift is observed in the peak of the absorption spectra with doping. The absorption coefficient alpha and extinction coefficient k were determined from the reflectance spectra in the strong absorption region. Moreover, the optical energy gap Eopt, increases with increasing Sb content.