A room-temperature alternating current susceptometer - Data analysis, calibration, and test

TL;DR

This paper presents a room-temperature AC susceptometer designed for characterizing magnetic nanoparticles and weakly magnetic materials, featuring a DAQ-based system, a novel calibration method, and a specific data acquisition strategy.

Contribution

It introduces a new AC susceptometer setup with a calibration method and data analysis approach for magnetic material characterization at room temperature.

Findings

Effective characterization of magnetic nanoparticles achieved.

Calibration method based on conductive samples validated.

System operates reliably across 10 Hz to 100 kHz frequency range.

Abstract

An AC susceptometer operating in the range of 10 Hz to 100 kHz and at room temperature is designed, built, calibrated and used to characterize the magnetic behaviour of coated magnetic nanoparticles. Other weakly magnetic materials (in amounts of some millilitres) can be analyzed as well. The setup makes use of a DAQ-based acquisition system in order to determine the amplitude and the phase of the sample magnetization as a function of the frequency of the driving magnetic field, which is powered by a digital waveform generator. A specific acquisition strategy makes the response directly proportional to the sample susceptibility, taking advantage of the differential nature of the coil assembly. A calibration method based on conductive samples is developed.