May 19, 2009
Author(s): Ross Dickinson , Jeremy Munn , Charles Amos , Dr. Chandra Prayaga , Dr. Laszlo Ujj , Dr. Guoqing Wu
AC magnetic susceptibility measurements, in which an AC magnetic field is applied to a sample and the resulting current/emf induced from the magnetization of electron moments in the sample is measured, are an important probe for characterizing many materials. In this effort, an innovative high-resolution AC susceptometer coil system (called AC susceptometer) is constructed, which provides us a capability to conduct state-of-the art experiments in AC magnetometry for important physics such as colossal magnetoresistance, superconductivity, charge/spin density wave and phase transitions occurring in the materials, and satisfy the needs of students‘ education in experimental science research. The design is adjustable so that it can match the size of a large or tiny specimen. Tests on this prototype system, using small samples have shown the capability to detect and measure signals on the order of nano-Volts. It adds a new experimental device and creates a novel vigorous area in research and science education at UWF. Future systems will have a built-in temperature controller, an integrated lock-in amplifier and an automated data acquisition capability. This creative activity is expected to lead to a US patent. No such device is commercially available currently in the US.