The stability of chip-size thermistors for miniature atomic clocks.

The AIST/NMIJ has been developing miniature atomic clocks to increase the availability of accurate time references. The behavior frequency of a miniature atomic clock is known to depend on the temperature. To obtain good prospects for the performance of miniature atomic clocks, it is necessary to evaluate the stability of thermistors installed within the main component. Six chip-sized thermistors selected from four manufacturers were evaluated. The chip-thermistors were mounted on silicon oxide substrates and their resistance values were measured alternately at two different temperatures: 0.01 °C and 80 °C. As a result, the magnitude of the resistance change, when converted to temperature, was found to be approximately 0.002 mK/day for the most stable chip thermistor, whereas the other chip thermistors exhibited a change of approximately 0.1 mK/day. [ABSTRACT FROM AUTHOR]