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Title: Heat capacity jump at T c and pressure derivatives of superconducting transition temperature in the Ba 1 - x Na x Fe 2 As 2 ( 0.1 x 0.9 ) series

Abstract

We present the evolution of the initial (up to ~ 10 kbar) hydrostatic pressure dependencies of T c and of the ambient pressure, and the jump in the heat capacity associated with the superconducting transition as a function of Na doping in the Ba1-xNaxFe2As2 family of iron-based superconductors. For Na concentrations 0.15 ≤ x ≤ 0.9, the jump in specific heat at T c, ΔC p| T$$_c$$, follows the ΔC p ∝ to T 3 (the so-called BNC scaling) found for most BaFe 2As 2 based superconductors. This finding suggests that, unlike the related Ba 1-xK xFe 2As 2 series, there is no significant modification of the superconducting state (e. g., change in superconducting gap symmetry) in the Ba 1-xNa xFe 2As 2 series over the whole studied Na concentration range. Pressure dependencies are nonmonotonic for x = 0.2 and 0.24. For other Na concentrations, T c decreases under pressure in an almost linear fashion. The anomalous behavior of the x = 0.2 and 0.24 samples under pressure is possibly due to the crossing of the phase boundaries of the narrow antiferromagnetic tetragonal phase, unique for the Ba 1-xNa xFe 2As 2 series, with the application of pressure. The negativemore » sign of the pressure derivatives of T c across the whole superconducting dome (except for x = 0.2) is a clear indication of the nonequivalence of substitution and pressure for the Ba 1-xNa xFe 2As 2 series.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science - Office of Basic Energy Sciences - Materials Sciences and Engineering Division
OSTI Identifier:
1356982
DOE Contract Number:  
AC02-06CH11357
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 89; Journal Issue: 1; Journal ID: ISSN 1098-0121
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English

Citation Formats

Bud'ko, Sergey L., Chung, Duck Young, Bugaris, Daniel, Claus, Helmut, Kanatzidis, Mercouri G., and Canfield, Paul C. Heat capacity jump at Tc and pressure derivatives of superconducting transition temperature in the Ba1-xNax Fe2As2 ( 0.1≤x≤0.9 ) series. United States: N. p., 2014. Web. doi:10.1103/PhysRevB.89.014510.
Bud'ko, Sergey L., Chung, Duck Young, Bugaris, Daniel, Claus, Helmut, Kanatzidis, Mercouri G., & Canfield, Paul C. Heat capacity jump at Tc and pressure derivatives of superconducting transition temperature in the Ba1-xNax Fe2As2 ( 0.1≤x≤0.9 ) series. United States. https://doi.org/10.1103/PhysRevB.89.014510
Bud'ko, Sergey L., Chung, Duck Young, Bugaris, Daniel, Claus, Helmut, Kanatzidis, Mercouri G., and Canfield, Paul C. Thu . "Heat capacity jump at Tc and pressure derivatives of superconducting transition temperature in the Ba1-xNax Fe2As2 ( 0.1≤x≤0.9 ) series". United States. https://doi.org/10.1103/PhysRevB.89.014510.
@article{osti_1356982,
title = {Heat capacity jump at Tc and pressure derivatives of superconducting transition temperature in the Ba1-xNax Fe2As2 ( 0.1≤x≤0.9 ) series},
author = {Bud'ko, Sergey L. and Chung, Duck Young and Bugaris, Daniel and Claus, Helmut and Kanatzidis, Mercouri G. and Canfield, Paul C.},
abstractNote = {We present the evolution of the initial (up to ~ 10 kbar) hydrostatic pressure dependencies of Tc and of the ambient pressure, and the jump in the heat capacity associated with the superconducting transition as a function of Na doping in the Ba1-xNaxFe2As2 family of iron-based superconductors. For Na concentrations 0.15 ≤ x ≤ 0.9, the jump in specific heat at Tc, ΔCp|T$_c$, follows the ΔCp ∝ to T3 (the so-called BNC scaling) found for most BaFe2As2 based superconductors. This finding suggests that, unlike the related Ba1-xKxFe2As2 series, there is no significant modification of the superconducting state (e. g., change in superconducting gap symmetry) in the Ba1-xNaxFe2As2 series over the whole studied Na concentration range. Pressure dependencies are nonmonotonic for x = 0.2 and 0.24. For other Na concentrations, Tc decreases under pressure in an almost linear fashion. The anomalous behavior of the x = 0.2 and 0.24 samples under pressure is possibly due to the crossing of the phase boundaries of the narrow antiferromagnetic tetragonal phase, unique for the Ba1-xNaxFe2As2 series, with the application of pressure. The negative sign of the pressure derivatives of Tc across the whole superconducting dome (except for x = 0.2) is a clear indication of the nonequivalence of substitution and pressure for the Ba1-xNaxFe2As2 series.},
doi = {10.1103/PhysRevB.89.014510},
url = {https://www.osti.gov/biblio/1356982}, journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {1098-0121},
number = 1,
volume = 89,
place = {United States},
year = {2014},
month = {1}
}