Frequency and applied field dependence of in-phase and out-of-phase odd harmonic susceptibilities of YBCO

Abstract

In-phase and out-of-phase components of the third, fifth, and seventh harmonic susceptibilities were obtained for polycrystalline YBCO. Frequency and field dependence were observed for frequencies ranging from 50Hz to 800Hz and fields ranging from 0.51mT to 3.64mT. In general, the harmonic signals as a function of temperature increases in magnitude with excitation frequency and applied magnetic field. The increase in magnitude with frequency and applied field was interpreted as a reflection of the increase in the nonlinearity of the sample's magnetic behavior. The shift in position in temperature with increasing applied magnetic field is similar in behavior to that of the intergranular loss peak at fundamental susceptibility, indicating a possible correlation between intergranular coupling and harmonic generation.