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Title: Microscopic parameters from high-resolution specific heat measurements on superoptimally substituted BaFe 2 ( As 1 - x P x ) 2 single crystals

Abstract

We investigate the electronic specific heat of superoptimally substituted BaFe 2(As 1-x P x) 2 single crystals in the superconducting state using high-resolution nanocalorimetry. From the measurements, we extract the substitution dependence of the condensation energy, superconducting gap Δ, and related microscopic parameters. We find that the anomalous scaling of the specific heat jump ΔC ∝ to T$$3\atop{c}$$ , found in many iron-based superconductors, in this system originates from a T c-dependent ratio Delta/k BT c in combination with a substitution-dependent density of states N(epsilon(F)). A clear enhancement is seen in the effective mass m* as the composition approaches the value that has been associated with a quantum critical point at optimum substitution. However, a simultaneous increase in the superconducting carrier concentration n s yields a penetration depth lambda that decreases with increasing T c without sharp divergence at the quantum critical point. Uemura scaling indicates that T c is governed by the Fermi temperature T F for this multiband system.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1352558
DOE Contract Number:  
AC02-06CH11357
Resource Type:
Journal Article
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 93; Journal Issue: 1; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Diao, Z., Campanini, D., Fang, L., Kwok, W. -K., Welp, U., and Rydh, A. Microscopic parameters from high-resolution specific heat measurements on superoptimally substituted BaFe2(As1-xPx)2 single crystals. United States: N. p., 2016. Web. doi:10.1103/PhysRevB.93.014509.
Diao, Z., Campanini, D., Fang, L., Kwok, W. -K., Welp, U., & Rydh, A. Microscopic parameters from high-resolution specific heat measurements on superoptimally substituted BaFe2(As1-xPx)2 single crystals. United States. https://doi.org/10.1103/PhysRevB.93.014509
Diao, Z., Campanini, D., Fang, L., Kwok, W. -K., Welp, U., and Rydh, A. Tue . "Microscopic parameters from high-resolution specific heat measurements on superoptimally substituted BaFe2(As1-xPx)2 single crystals". United States. https://doi.org/10.1103/PhysRevB.93.014509.
@article{osti_1352558,
title = {Microscopic parameters from high-resolution specific heat measurements on superoptimally substituted BaFe2(As1-xPx)2 single crystals},
author = {Diao, Z. and Campanini, D. and Fang, L. and Kwok, W. -K. and Welp, U. and Rydh, A.},
abstractNote = {We investigate the electronic specific heat of superoptimally substituted BaFe2(As1-x Px)2 single crystals in the superconducting state using high-resolution nanocalorimetry. From the measurements, we extract the substitution dependence of the condensation energy, superconducting gap Δ, and related microscopic parameters. We find that the anomalous scaling of the specific heat jump ΔC ∝ to T$3\atop{c}$ , found in many iron-based superconductors, in this system originates from a Tc-dependent ratio Delta/kBTc in combination with a substitution-dependent density of states N(epsilon(F)). A clear enhancement is seen in the effective mass m* as the composition approaches the value that has been associated with a quantum critical point at optimum substitution. However, a simultaneous increase in the superconducting carrier concentration ns yields a penetration depth lambda that decreases with increasing Tc without sharp divergence at the quantum critical point. Uemura scaling indicates that Tc is governed by the Fermi temperature TF for this multiband system.},
doi = {10.1103/PhysRevB.93.014509},
url = {https://www.osti.gov/biblio/1352558}, journal = {Physical Review B},
issn = {2469-9950},
number = 1,
volume = 93,
place = {United States},
year = {2016},
month = {1}
}