MAGNETORESISTANCE OF THICK-FILM CHIP RESISTORS AT MILLIKELVIN TEMPERATURES

Data are presented for the magnetoresistance of two types of commercial thick-film chip resistors in the millikelvin temperature regime (1 k Omega Dale RCW-575 and 2.7 k Omega Philips RC-01). Chip resistors, which are intended for use in microcircuit electronics, have become an important tool in low temperature research due to their applicability as reliable secondary thermometers. They have good reproducibility and fast thermal response, are small and are easy to mount. The temperature range covered in this work is between 1 K and 25 mK, and the magnetic field range is from 0 to 7 T. For both resistors, the magnetoresistance (MR) is negative for low magnetic fields, and positive for high fields. The transition point from negative to positive MR and the magnitude of the MR are strongly temperature dependent. At 25 mK and 7 T, which are the lowest temperature and the highest field measured, the MR value is a few per cent. On average, the MR of the Philips resistor is approximate to 50% lower than that of the Dale resistor.