Magnetoresistance of Silver Bromide

Abstract

The magnetoresistance effect was investigated in high-purity zone-refined AgBr in order to obtain information about the conduction band structure in this material. The measurements were performed at 2\ifmmode^\circ\else\textdegree\fi{}K and in magnetic fields up to 18 kG. The rate-of-drift method using a sensitive electrometer was employed to observe the transient photoconductivity both in the presence and absence of a magnetic field. Results of the experiments are consistent with the assumption of a spherically symmetric conduction band centered at $k=0$ as well as with an electron relaxation time of the form: $\ensuremath{\tau}={\ensuremath{\tau}}_{0}{(\frac{\ensuremath{\epsilon}}{\mathrm{KT}})}^{\frac{3}{2}}$, with ${\ensuremath{\tau}}_{0}=1.1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}$ sec. During the course of the magnetoresistance measurements, a deviation from Ohm's law at high electric fields was noted. Some data on this "hot electron" effect are presented and briefly discussed.