The contactless measurement of the electrical resistivity

Physicists are interested in understanding the processes of nature. Within the field of Solid State Physics the characterisation of materials and the measurement of their properties is the first step towards identifiying new and interesting areas of scientific activities. The electrical resistivity of conductive materials is an important property which provides information about the electronic behaviour of the material. An elegant method to determine this characteristic is the measurement without using electrical contacts. Such a method avoids a whole set of experimental problems connected with the physics of electrical contacts to the sample. This Master-thesis gives an introduction into this experimental technique. A detailed theoretical description is developed. The experimental activity has involved the design, construction and testing of the apparatus. In the process of testing the method novel aspect emerged: The measurement at resonance point. These measurements can yield separate values for two different physical quantities: the electrical resistivity e and the magnetic susceptibility x. The innovation of this project is the simultaneous characterisation of both values for the material under investigation. The report starts by giving the theoretical background within which the first part of the detailed theoretical predictions are discussed. The second part contains experiments and a description of the experimental set-up. This design is the result of a long period of optimisation and testing. The working of the apparatus is demonstrated by the measurement of some samples.