Anomalous temperature dependence of the amplitude of longitudinal Shubnikov–de Haas oscillation

Temperature dependence of the longitudinal magnetoresistance has been measured for bismuth single crystals doped with a small amount of antimony (0.1, 0.3, 0.6, 1.0, 1.5 and 2.3 at%) up to 5 T of magnetic field in the temperature range between 1.2 and 23 K. The amplitude of longitudinal Shubnikov–de Haas (SdH) oscillations for the doped samples is markedly enhanced with decreasing temperature in spite of the Landau level broadening. To understand this anomaly, a simple numerical simulation is made for studying how the oscillation amplitude is affected by the temperature as well as impurity. This simulation supports the fact that the increase in the number of scattering centers and the lower value of damping factor of the SdH oscillation due to impurity-doping lead to the large amplitude at lower temperatures. The Dingle term became dominant at higher temperatures.