Temperature Dependence of the Characteristic Energy Loss of Electrons in Aluminum

The change in the 15-ev characteristic energy loss suffered by 15-kev electrons passing through a thin film of aluminum has been measured as a function of temperature from 4.2 K to 518 K. It is found that above room temperature the energy loss change agrees, within experimental error, with the change expected due to decreased electron density resulting frozn expansion of the lattice. However, below room temperature the energy loss change is much greater than expected on the above basts. It was also found that the half-widths of both the energy loss and the zero loss lines increased with decreasing temperature while the ratio or these two remined constant. (auth)