Measurements of magnetomorphic effects in indium films of thickness between 0.003 and 0.01 cm have been made at 4.2 and 1.5°K. The results were compared with theoretical calculations based on the free-electron model. To make these comparisons, it was necessary to discount the bulk magnetoresistance by means of a modified Kohler's rule suggested by Olsen. From the comparison of the data with the theory, it was possible to deduce the values of the electronic momentum $\mathrm{mv}$ and the product of the bulk resistivity with the bulk mean free path ${\rho }_{b}l$. Data previously obtained by Olsen in wires have been analyzed with the use of measurements of Kohler's rule and of a criterion for the comparison different from the one used by Olsen. The experimental value of ${\rho }_{b}l$ is discussed on the basis of an analysis made by Bate et al., in which the anisotropy of the mean free path is taken into account.

• Received 22 May 1967

DOI:https://doi.org/10.1103/PhysRev.163.575