Measurement of Hall conductivity near the metal insulator transition by torque magnetometry

We study Hall conductivity near the disorder-induced metal-insulator transition and present the first measurements of Hall conductivity utilizing a torque magnetometry method. A Corbino disk exhibits a magnetic dipole moment proportional to Hall conductivity when voltage is applied across a test material. This magnetic dipole moment can be measured through torque magnetometry. The symmetry of this contactless technique allows us to measure the Hall conductivity of insulating materials and materials near the metal-insulator transition such as sputtered indium tin oxide. We have measured the Hall conductivity of indium tin oxide with a ratio of transverse to longitudinal resistivity of 1E-4 and can now measure Hall conductivity independently of longitudinal resistance.