Temperature Coefficient of Electrical Resistivity for Crystalline Selenium Containing Various Percentages of Bromine

Abstract

The temperature coefficient of electrical resistance of brominated selenium over the temperature range −30°C to 100°C was found to be negative and variable. The electrical resistivities of the selenium samples varied by factors of three to twelve for the temperature range mentioned, depending upon the bromine content. A reproducible hysteresis loop was obtained on the plot of resistivity versus temperature. A minimum in the plot of electrical resistivity versus bromine content was found with 0.007 percent bromine in selenium. Activation energies for freeing electrons obtained from the slopes of conductivity versus temperature plots indicate a dependence upon bromine content in the selenium.