Critical Current and Pinning Features of a CaKFe<sub>4</sub>As<sub>4</sub> Polycrystalline Sample

oleh: Armando Galluzzi, Antonio Leo, Andrea Masi, Francesca Varsano, Angela Nigro, Gaia Grimaldi, Massimiliano Polichetti

Format: Article
Diterbitkan: MDPI AG 2021-11-01

Deskripsi

We analyze the magnetic behavior of a CaKFe4As4 polycrystalline sample fabricated by a mechanochemically assisted synthesis route. By means of DC magnetization (M) measurements as a function of the temperature (T) and DC magnetic field (H) we study its critical parameters and pinning features. The critical temperature T<sub>c</sub> has been evaluated by M(T) curves performed in Zero Field Cooling-Field Cooling conditions. These curves show the presence of a little magnetic background for temperatures above T<sub>c</sub>, as also confirmed by the hysteresis loops M(H). Starting from the M(H) curves, the critical current density J<sub>c</sub> of the sample has been calculated as a function of the field at different temperatures in the framework of the Bean critical state model. The J<sub>c</sub>(H) values are in line with the ones reported in the literature for this typology of samples. By analyzing the temperature dependence of the critical current density J<sub>c</sub>(T) at different magnetic fields, it has been found that the sample is characterized by a strong type pinning regime. This sample peculiarity can open perspectives for future improvement in the fabrication of this material.