High-sensitivity vector magnetometer for measuring magnetic torque at low temperatures

Abstract

We present a fully automated vector vibrating-sample magnetometer where the sample can be rotated against the applied magnetic field Hap, so that the angular dependence of the longitudinal, Mlong, and transversal, Mtrans, components of M with respect to Hap on the rotation plane are determined. The magnetic field range is ±20 kOe and temperature ranges between 4.2 and 340 K. The resolution is better than 2×10–7 emu and the sensitivity is 5×10–6 emu. Standard hysteresis loop measurements are possible as well. As examples of its capability we display torque curves performed at low temperatures in a [Ho8Lu15]50 superlattice and in a 60-nm-thick Terfenol-D thin film.