Magnetoresistance of Silver Bromide

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°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 $k=0\mathrm{}$ as well as with an electron relaxation time of the form: $\tau ={\tau }_0{\left(\frac{\epsilon }{\mathrm{KT}}\right)}^{\frac{3}{2}}$, with ${\tau }_0=1.1\mathrm{}\times {10}^{-12\mathrm{}}$ 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.