Frequency Dependence of the Higher Harmonics Susceptibilities of Hydrogen Loaded and Unloaded Melted YBCO Samples

We measured the first and higher components of ac susceptibilities of melted YBCO samples before and after hydrogenation by ms pulsed electrolysis. First component was measured versus temperature at fixed frequency while higher harmonics were measured versus frequencies at fixed temperature near critical temperature. All measurements were performed at fixed amplitude of ac magnetic field and zero dc magnetic field. The frequency and temperature behavior of the harmonic components before and after hydrogenation gave us information on possible dynamic losses in comparison to the flux pinning mechanism.