Scattering of Carriers by Magnetic Mn Impurities in PbTe: Mn Alloys

The carrier mobility and the spin exchange between carriers and localized magnetic Mn impurities are studied in $p$-type PbTe: Mn alloys. Using helicon propagation, the mobility measurements lead to a value for the total manganese impurity cross section ${\sigma }_{\mathrm{scatt}}=5\mathrm{}\times {10}^{-16\mathrm{}}$ ${\mathrm{cm}}^2$. The linewidth of the Mn electron spin resonance is studied as a function of temperature, number of carriers, and manganese concentration. The carrier-dependent linewidth is explained in terms of a Korringa mechanism. From this analysis, the exchange constant $J=0.07\mathrm{}$ eV is deduced. From this value of $J$, the spin-flip scattering cross section ${\sigma }_{\mathrm{sf}}=4\mathrm{}\times {10}^{-19\mathrm{}}$ ${\mathrm{cm}}^2$ is calculated.