The measurements of the first and the third harmonics of the AC magnetic susceptibility, performed on melt grown YBCO samples as a function of the temperature and the external parameters (frequency and amplitude of AC magnetic field, intensity of a DC field) were studied by using the Cole–Cole plot analysis. By considering the AC field dependence of the third harmonics Cole–Cole plots, we have extracted information about the peculiar behaviour of the I–V characteristics and, therefore, about the dissipative phenomena in the sample. The experimental results have been analysed with the help of both analytical and numerical curves. In particular, the use of a phenomenological expression for the resistivity allowed us to reproduce the main experimental features, including the observed invariance of the area inside the Cole–Cole plots and their behaviour as a function of the AC field.
Harmonics of the AC susceptibility for the study of I-V curves in melt grown YBCO
POLICHETTI, Massimiliano;PACE, Sandro
2004
Abstract
The measurements of the first and the third harmonics of the AC magnetic susceptibility, performed on melt grown YBCO samples as a function of the temperature and the external parameters (frequency and amplitude of AC magnetic field, intensity of a DC field) were studied by using the Cole–Cole plot analysis. By considering the AC field dependence of the third harmonics Cole–Cole plots, we have extracted information about the peculiar behaviour of the I–V characteristics and, therefore, about the dissipative phenomena in the sample. The experimental results have been analysed with the help of both analytical and numerical curves. In particular, the use of a phenomenological expression for the resistivity allowed us to reproduce the main experimental features, including the observed invariance of the area inside the Cole–Cole plots and their behaviour as a function of the AC field.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
