Phase and frequency control in the vibrating wire magnetic susceptometer

The recently developed vibrating wire susceptometer (VWS) is an instrument inherently suitable to perform measurements with high sensitivity in a wide temperature range (up to 1200 K). In the present work we describe the principle of the electronic control of phase and frequency of the VWS that allows accurate determination of both the real and imaginary part of the susceptibility. In particular, the high quality factor, intrinsic to the mechanical system of the VWS, allows in principle to detect very small energy losses due to magnetic dissipative processes in the specimen.