Even harmonic generation of YBCO with intergranular coupling

Abstract

Harmonic responses were obtained for two polycrystalline YBCO. Sample 1 of smoother surface morphology and less defined grain boundaries produces even harmonics, while sample 2 does not. A minor difference in the fundamental out-of-phase susceptibility is the slight overlap of intergranular and intragranular loss peaks for the rough sample. Other than the slight convergence, no distinct difference is observed in the magnetic behavior of the two samples. The odd harmonics of the two samples display the same behavior. Only the surface morphology clearly distinguishes the samples from one another, the presence of even harmonic is inferred to be dependent on granularity.