EFFECT OF TEMPERATURE ON RADIATION-DAMAGE TO AROMATIC ORGANIC-MOLECULES

This work examines the effect of temperature on the rate of damage caused by the electron beam in the microscope. Oriented single-crystal films of aromatic organic compounds have been used as specimens between 4 and 293 K. It is shown that the rate of damage is a function of the thickness and specimen temperature for any one compound, and that the rates of damage to the same specimen-exponentially related to reciprocal temperature. The Arrhenius plots reveal two activation energies for the degradation reactions with the higher activation energy ceasing at approximately 80 K. It would be expected that significant advantages in specimen lifetime would be obtained in specimens examined below this temperature.