Print version ISSN 0122-7483
We assembled a Hall effect and electric conductivity measuring unit that allows the determination of transport properties in semiconductor and metal films, including the type and concentration of majority carriers and their mobility, from measurements of Hall voltage and current. It is clear that electrons are the charge carrier in metals, however some metals such as aluminum, zinc and cadmium among others exhibit a behavior that, according to the classical view, should be positive charge carriers (holes). In this paper we discuss Hall effect measurements in two types of materials: copper (Cu) and zinc (Zn). Results from measurements show that copper has a negative Hall coefficient RH = - (0.28 ± 0.01)×10-10 m3/C and zinc has a positive coefficient RH = + (4.2 ± 0.2)×10-11 m3/C. Our results agree with those reported in the scientific literature. Most of the textbooks on solid state physics do not mention explicitly the reason why some metals show a positive Hall coefficient. We discuss this fact based on their band structures.
Keywords : Hall effect; semiconductor; metal; LabVIEW.