An AC Susceptometer Design and Magnetic Susceptibility Measurements on Nickel Wire

Date of Award


Document Type


Degree Name

Master of Science (MS)


Physics & Astrophysics


It is found from the literature that magnetic susceptibility data on nickel (Ni) do not come from direct measurements. Most of the magnetic susceptibility data of Ni come from the calculation of the slope of magnetic moment vs. temperature curves, and the magnetic moment data are measured in air. In modem research, film samples are used very often. Many of metal films are easily oxidized. Oxidation may change the magnetic properties of the magnetic films. To avoid oxidation, magnetic susceptibility measurements should be carried out in high vacuum For this reason we have designed an ac susceptometer which can be placed in an ultrahigh vacuum chamber to perform direct magnetic susceptibility measurements. To show that this setup does work, we performed a series of ac inductance measurements on a Ni wire using the setup. Our data indicated that the magnetic susceptibility of nickel near the paramagnetic to ferromagne tic transition follows a 4/3 power law in good agreement with theoretical prediction. Except for a 2 K temperature shift, our data agree very well with those calculated by Kouvel and Fisher using the magnetic moment data of Weiss and Forrer. This indicates that our experimental setup works. The 2 K temperature discrepancy is within the manufacturer’s specification of the temperature controller.

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