At Nanolab, we have a Hall and Van Der Pauw measurement system of MMR technology to characterize the electrical properties of SiC and GaN thin-films as well as the starting substrates. It includes a K-20 programmable temperature controller, H-50 Hall and Van Der Pauw controller, MPS-50 programmable power supply, M-50 benchtop electromagnet, MMR thermal stage with cryogenic refrigerator, Dewar and vacuum accessories. System control is provided by an IBM compatible computer. The K-20 temperature controller adjusts and maintains the temperature of the MMR thermal stage over a wide temperature range, with high accuracy and stability. The H-50 Hall and Van Der Pauw controller provides four probe method measurements of the electrical parameters of the samples. The M-50 benchtop electromagnet provides the magnetic field over the studied sample and the MPS-50 programmable power supply controls the magnitude of that magnetic field. These scientific instruments were designed as separate computer controlled devices. This MMR's Hall System allows the user to make automatic measurements of resistivity, mobility and carrier concentration of a wide range of samples using the Van der Pauw method over a temperature range from 80 K to 400 K. The whole set up is shown in the attached picture.