NiCr based thin film cryo resistors

Thin film resistors, based on the NiCr alloys, have been fabricated and studied at temperatures down to 50 mK. Resistivity of the films varied within (7-11) Ohm*square depending on additions of Cu, Al and Ge. The resistors demonstrate Kondo minimum at 20 K - 30 K. Power dependence measurements at sub Kelvin temperatures showed an electron overheating at the power level above 10 pW for the Ni
₇₅
Cr
₂₀
Cu
_2.5
Al
_2.5
(Evanohm) 500 kOhm film resistor.