The effect of substrate temperatures on the Hall coefficient of α-Mn thin films

Hall coefficient measurements in evaporated α-Mn thin films have been carried out in magnetic fields up to 63 kG in the temperature range between 1.5 and 100 K using the van der Pauw four probe technique. The results show a range of temperature variation of the Hall coefficient (RH) depending upon the substrate temperatures used. At high substrate temperatures (Ts > 100 °C) and in high vacuum the sign of RH changes from negative to positive as the temperature is lowered from 100 to 1.5 K, whilst at low substrate temperatures (Ts 30 °C) and in a similar vacuum the sign of RH remains negative. The results of the Hall coefficient in the films are analysed using the two band model of conduction with temperature independent carrier concentrations.