โ Scribed by C. Beduz; H.C. Meijer; G.J.C. Bots
No coin nor oath required. For personal study only.
Several aspects of carbon thermometry below 1 K are discussed. Some calibrations, performed on home-made carbon resistors, are presented. The lowest reliable calibration temperature was 25 mK. The reproducibility after thermal cycling of these resistors appeared to be good. Comments are given on our measurements, and also on those of others. It is very probable that the thermal resistance between the spin system and the lattice of the cooling salt is in many cases the main obstacle to the attainment of a low resistor temperature.
๐ SIMILAR VOLUMES
The simple temperature dependence of carbon and germanium resistors in the variable-range hopping regime is applied for thermometry below 1 K. The linear dependence of In(R) on T -x (1/4 ~< x ~< 1/2) does not require the usual fitting procedure and makes calibration and thermometry more convenient.