Construction of a Shielded Thermal Hall Measurement Device
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Date
2023-05-26
Authors
Biggart, Kaylee
Journal Title
Journal ISSN
Volume Title
Publisher
University of Waterloo
Abstract
A shielded thermal Hall experimental setup is being constructed and is nearing
completion. An existing conventional thermal conductivity experiment
was retrofit to perform thermal Hall measurements, which included the addition
of coaxial cables to a low-temperature probe. A copper sample puck
was machined and encases the sample, thermometers, and sample heater, to
reduce mechanical stress and shield from electromagnetic radiation. SrTiO3
wafers were fabricated into capacitive thermometers by evaporating gold onto
either side of each wafer, and thermally resistive wires to provide electronic
connection to thermometers and sample heater were fabricated by evaporating
gold onto Kapton.
Preliminary testing at liquid nitrogen temperatures was performed on a sample
of silver wire. Complications arose that prevented thermal conductivity
or thermal Hall measurements from being performed at liquid nitrogen temperatures,
but the sensitivity and temperature resolution of the capacitive
thermometers was tested and found to be sufficient for detecting thermal
Hall signals. It became clear that the original fabrication method used for
the capacitive thermometers and Kapton wires was not robust enough to
prevent the electronic components from degrading upon thermal cycling, so
the use of titanium adhesion layers was explored with regards to adhering
gold to SrTiO3 and Kapton. Once the fabrication process for the capacitive
thermometers and Kapton wires has been perfected, thermal Hall measurements
can be performed using the experimental setup as described in this
work.