  The design, manufacture and characterisation of an inexpensive, temperature
controlled vacuum chamber with millikelvin stability for electrical transport
measurements at and near room temperature is reported. A commercially available
Peltier device and high-precision temperature controller are used to actively
heat and cool the sample space. The system was designed to minimise thermal
fluctuations in spintronic and semiconductor transport measurements but the
general principle is relevant to a wide range of electrical measurement
applications. The main issues overcome are the mounting of a sample with a path
of high thermal conductivity through to the Peltier device and the heat-sinking
of said Peltier device inside of a vacuum. A copper slug is used as the mount
for a sample and a large copper block is used as a thermal feedthrough before a
passive heatsink is used to cool this block. The Peltier device provides 20 W
of heating and cooling power achieving a maximum range of 30 K below and 40 K
above the ambient temperature. The temperature stability is within 5 mK at all
set points with even better performance above ambient temperature. A vacuum
pressure of 1e-8 hPa is achievable. As a demonstration, we present experimental
results from current-induced electrical switching of a CuMnAs thin film.
Transport measurements with and without the Peltier control emphasise the
importance of a constant temperature in these applications. The thermal lag
between the sample space measurement and the sample itself is observed through
magnetoresistance values measured during a temperature sweep.
