Methods for Investigating the Thermal Hall Effect up to 32T

Currently, the bulk of thermometers used in cryogenic experiments are resistive thermometers such as Cernox and ruthenium oxide. However, under high magnetic fields (>5T), the aforementioned thermometers have magnetoresistance of several percent, causing them to be either unreliable or require extensive calibration. We explore two potential compounds that are much more stable in similar temperatures and fields. Strontium titanate (SrTiO₃) is an effective capacitive thermometer that varies only by a few hundredths of a percent at high fields. We show that oxygen-18 exchanged strontium titanate thermometers can be used as the sensor for temperature control in the millikelvin range, and hope to adapt them for thermal transport measurements. Gold germanium (AuGe) is a resistive thermometer that has a much smaller magnetoresistance (~1%) and does not have the bulk or wiring issues of capacitive thermometry. We explore avenues to apply it as a thin-film thermometer for thermal transport measurements.