Methods for Increasing the Spatial Resolution and Sensitivity of Classical Hall Magnetometers

Attention is drawn to the effect of the self-field HHT of bias current IHT through a Hall transducer (HT) on the objects of study and the measurement accuracy of the Hall magnetometer. The field HHT of the n-InSb-i-GaAs heteroepitaxial HT is considered. It is found that the force lines of the induction of HHT undergo a stepwise change in their direction at the edges of a thin epitaxial n-InSb film. In the case of nonuniform distribution of IHT over the cross section of the film, these jumps create a voltage across the Hall contacts due to the anisotropy, growth-induced defects, and nonequipotentiality of the Hall contacts, thus, leading to the measurement error. Exact compensation of HHT by the field of a current in antiphase to IHT makes it possible not only to eliminate the effect of the self-field on the objects of study but also to lower the detection threshold of the magnetometer from approximately 2.5 × 10–7 to approximately 5.75 × 10–9 T in the range of fields from 2.5 × 10–9 to 5 × 10–7 T and temperatures from 77.4 to 150 K.