Investigation on flicker noise of overtones and anharmonic modes of ultra-stables quartz crystal resonators

In this paper, prototypes of SC-cut resonators with 5 MHz resonant frequency are presented. The resulting short-term stability of some resonators has been measured lower than 8·10 ^-14 in terms of Allan standard deviation. The results are compared according to the overtone behavior on different vibrating modes to find a correlation with the intrinsic noise of the resonators. The comparison of these resonators is given in terms of motional parameters and Q-factors measured at room temperature and at low temperature.