Model calculations for the high-field peak of the fish-tail effect in the magnetostriction of type-II superconductors

We have aimed to describe the peak-effect observed in various magnetostriction experiments of type-II superconductors in the framework of critical-state models. A Gaussian term added to the exponential model and a Lorentzian term added to the Kim model for the field dependences of critical current density were employed in the calculations. The equations were solved numerically to obtain flux profiles inside a superconducting sample and thus to form the curves of magnetostriction versus applied field. The exponential model was also employed to reproduce the magnetostriction measurements performed on a single crystal 2H-NbSe2 carried out by Eremenko et al. [Low Temp. Phys. 27 (2001) 305].