Demagnetization induced peak effect for a FeSeTe granular superconductor in ac magnetic field

The possible evidence of a peak effect in the temperature dependent magnetization and in the field dependent critical current density has been found for a FeSeTe superconducting granular sample in presence of an ac field. The existence of the peak effect has been confirmed by the numerical calculation of the inter- A nd intragranular magnetizations in presence of a demagnetization field with components at the third harmonic frequency generated by the sample magnetization. This suggests that the peak effect could be related to the flux dynamics inside the sample through the demagnetization field third harmonic.