Thermoelectric Properties of Metals and Semiconductors

Nonstoichiometric oxide phases are of great importance in semiconductor devices, in heterogeneous catalysis and in understanding photoelectric, thermoelectric, magnetic and diffusional properties of solids. They have been used in thermistors, photoelectric cells, rectifiers, transistors, phosphors, luminescent materials and computer components (ferrites, etc.). They are cmcially implicated in reactions at electrode surfaces, the performance of batteries, the tarnishing and corrosion of metals, and many other reactions of significance in catalysis. ... 

The absolute values and the nature of the tenq)erature dependences of tiie thermoelectric properties of iron mon-osilicide (Fig. 1) indicate that it is a semiconductor below room temperature and a metal at higher temperatures the calculated value of the activation energy of the carriers is about 0.05 ev (data on the semiconductor nature of the temperature dependence of Upesi 1° good agreement with results in [17], althou the value AE 0.5 eV quoted in [17] is incorrect). 

The silver white, shiny, metal-like semiconductor is considered a semimetal. The atomic weight is greater than that of the following neighbor (iodine), because tellurium isotopes are neutron-rich (compare Ar/K). Its main use is in alloys, as the addition of small amounts considerably improves properties such as hardness and corrosion resistance. New applications of tellurium include optoelectronics (lasers), electrical resistors, thermoelectric elements (a current gives rise to a temperature gradient), photocopier drums, infrared cameras, and solar cells. Tellurium accelerates the vulcanization of rubber. 

---