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© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.

Abstract

Among various “families” of iron-based superconductors, the quite recently discovered AeAFe4As4 (where Ae is an alkali-earth metal and A is an alkali metal) has high critical current density, a very high upper critical field, and a low anisotropy, and has recently received much interest for the possibility of high magnetic field applications at the liquid hydrogen temperature. We have performed DC magnetization relaxation and frequency-dependent AC susceptibility measurements on high-quality single crystals of CaKFe4As4 with the aim of determining the pinning potential U*. The temperature dependence of U* displays a clear crossover between elastic creep and plastic creep. At temperatures around 27–28 K, U* has a very high value, up to 1200 K, resulting in an infinitesimally small probability of thermally activated flux jumps. From the dependence of the normalized pinning potential on irreversible magnetization, we have determined the creep exponents in the two creep regimes, which are in complete agreement with theoretical models. The estimation of the pinning potential from multifrequency AC susceptibility measurements was possible only near the critical temperature due to equipment limitations, and the resulting value is very close to the one that resulted from the magnetization relaxation data. Magnetic hysteresis loops revealed a second magnetization peak and very high values of the critical current density.

Details

Title
Vortex Dynamics and Pinning in CaKFe4As4 Single Crystals from DC Magnetization Relaxation and AC Susceptibility
Author
Ionescu, Alina M 1 ; Ion, Ivan 1 ; Miclea, Corneliu F 1 ; Crisan, Daniel N 1   VIAFID ORCID Logo  ; Galluzzi, Armando 2   VIAFID ORCID Logo  ; Polichetti, Massimiliano 2   VIAFID ORCID Logo  ; Crisan, Adrian 1   VIAFID ORCID Logo 

 National Institute of Materials Physics, 405A Atomistilor Str., 077125 Magurele, Romania; [email protected] (A.M.I.); [email protected] (I.I.); [email protected] (C.F.M.); [email protected] (D.N.C.) 
 Department of Physics “E.R. Caianiello”, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy; [email protected] (A.G.); [email protected] (M.P.) 
First page
93
Publication year
2023
Publication date
2023
Publisher
MDPI AG
e-ISSN
24103896
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2904635664
Copyright
© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.