On the nature of the maximum of the longitudinal magnetoresistance in thin films of bismuth and bismuth–antimony alloys
Abstract
The behavior of the maximum in the longitudinal magnetoresistance in bismuth and Bi-Sb alloy thin films with changes in the thickness and alloy composition has been studied. It is proposed that the decrease in the film resistance in a strong magnetic field occurs basically due to the growth in the carrier concentration upon reaching the ultraquantum field region. The position of the maximum of the longitudinal magnetoresistance does not depend on L for sufficiently great film thicknesses (with L ≳3000–4000 Å for Bi and with L ≳ 6000–8000 Å for Bi0.963Sb0.037 alloys). With a lower thickness the field at the maximum increases due to the change in the parameters of the spectrum and the growth of the carrier concentration. A dependence of the form Hmax3/2∼1/L agrees well with the proposed explanation of the nature of the maximum of the longitudinal magnetoresistance.