Measurement of electrical resistivity using a non-contact method.*

Reliable measurements of the electrical resistivity are essential to understand the electronic behavior of a material. Conventional methods such as van der Pauw [1] measurements rely on physical contacts for wires, which can be difficult or impossible to make for small and/or delicate samples [2]. In this work, we demonstrate resistivity measurements with a contactless method that involves the generation and detection of eddy currents. Our probe operates between 77 K and 300 K, with very low background signal levels, enabling accurate measurements of sample resistivity. This temperature range could be extended with changes to the design. We will present results for several oxide superconductors that have undergone various heat and pressure treatments aimed to study the effects of plastic deformation [3] and hole doping on resistivity.

[1]    P. Hemenger, Rev. Sci. Instrum. 44, 698 (1973).

[2]    M. Doslic, D. Pelc, M.Pozek, Rev. Sci. Instrum. 85, 073905 (2014).

[3]    S. Hameed et al., Nat. Mater. (2021); https://www.nature.com/articles/s41563-021-01102-3.