Review of Scientific Instruments
The reported nearly constant temperature sensitivity of appropriately annealed polycrystalline AuxGe1-x thin films at cryogenic temperatures would appear to make them promising materials for low mass, rapid thermal response resistive thermometers, but their adoption has been limited by difficulties in fabrication and uncertainties in annealing. In this work, we present a method of fabrication and annealing which allows control of the two most important parameters for these films: the room-temperature resistivity ρRT and the temperature sensitivity η(T), where η ≡ -d In R/d In T. We find that the dependence of ρRT on total anneal duration t for x≈0.18 is given by ρRT=ρ∞[1-Aexp(-t/τ)], where the limiting room-temperature resistivity ρ∞, the annealing coefficient A, and relaxation time τ are annealing temperature dependent parameters. The dependence of ρRT and temperature calibration ρ(T) on anneal duration can be minimized by annealing above 250 °C. Like ρRT, the sensitivity η(T) also depends on annealing temperature, with higher annealing temperatures corresponding to lower cryogenic sensitivities. In all cases η(T) can be well described by a polynomial expansion in In T from room temperature down to at least 2 K.
© 1998 American Institute of Physics.
Fortune, Nathanael A.; Graf, Michael J.; and Murata, Keizo, "Physical Dependence of the Sensitivity and Room-Temperature Stability of AuxGe1-x Thin Film Resistive Thermometers on Annealing Conditions" (1998). Physics: Faculty Publications, Smith College, Northampton, MA.