The paper is a result of a collaboration between Lake Shore, and scientists from the University of Texas at Austin, Washington State University, and the Pacific Northwest National Laboratory. The paper presents variable temperature, cryogenic, and AC field Hall data for a single crystal of BiVO4. This material is a possible photo-anode for direct conversion of sun light to H2.
The group had originally used DC fields to measure the Hall effect of this material, but were not able to obtain a clear signal, as the mobility was too small. The mobility was 0.2 cm2/(V s) and the resistivity at 175K was 350 megohm/sqr. The group then used the AC field Hall effect method to facilitate measurement of the Hall effect. Section 3.3.3 "Hall effect measurements" of the paper gives an explanation of how the AC Hall effect was used to obtain these measurements.
You can read the full abstract and obtain the paper from the Journal of the American Chemical Society.