Temperature Dependence of Electron Mobility in AgCl

By using improved crystal counter techniques, electron mobility has been investigated as a function of temperature in AgCl. The measurements were made on annealed samples carefully grown from the melt in which the range of conduction electrons was of the order of ${10}^{-4\mathrm{}}$ cm per volt/cm of electric field strength. At high fields electron trapping in the volume of the crystal is less important and observed mobility is shown to become a constant independent of field. At 86°K, drift mobility was found to be 274 ${\mathrm{cm}}^2$/volt sec and was reproducible to within 10 percent for several samples. The data on mobility can be fitted down to 86°K by an expression of the form $\mu =2.54\mathrm{}\times {10}^5{T}^{-\frac{3}{2}}$, which would suggest interaction of the electrons mainly with acoustic vibrations of the lattice. However, there exists the possibility of scattering by impurities or other imperfections which in combination with optical scattering might also lead to the observed results. Strains play an important role in this material and are shown to be associated both with shallow 0.1-ev traps and with deeper traps. The average energy for production of one electron-hole pair by beta rays is 7.5±0.5 ev. The range of holes in the samples tested, from 86°K to 150°K, was at least less than $\frac{1}{10}$ that of electrons.