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Related papers: The superconducting gaps in LiFeAs: Joint study of…

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We have fabricated c-axis point contact junctions between high-quality LiFeAs single crystals and Pb or Au tips in order to study the nature of the superconducting order parameter of LiFeAs, one of the few stoichiometric iron-based…

Superconductivity · Physics 2012-04-06 Xiaohang Zhang , Bumsung Lee , Seunghyun Khim , Kee Hoon Kim , Richard L. Greene , Ichiro Takeuchi

We report the specific heat (SH) measurements on single crystals of hole doped $FeAs$-based superconductor $Ba_{0.6}K_{0.4}Fe_2As_2$. It is found that the electronic SH coefficient $\gamma_e(T)$ is not temperature dependent and increases…

Superconductivity · Physics 2009-05-02 Gang Mu , Huiqian Luo , Zhaosheng Wang , Lei Shan , Cong Ren , Hai-Hu Wen

Temperature and fluence dependence of the 1.55-eV optical transient reflectivity in BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ was measured and analysed in the low and high excitation density limit. The effective magnitude of the superconducting…

Superconductivity · Physics 2015-10-14 A. Pogrebna , T. Mertelj , Z. R. Ye , D. L. Feng , D. Mihailovic

The in-plane thermal conductivity $\kappa$ of electron-doped iron-arsenide superconductor BaFe$_{1.9}$Ni$_{0.1}$As$_2$ ($T_c$ = 20.3 K) single crystal was measured down to 70 mK. In zero field, the absence of a residual linear term…

Superconductivity · Physics 2015-05-13 L. Ding , J. K. Dong , S. Y. Zhou , T. Y. Guan , X. Qiu , C. Zhang , L. J. Li , X. Lin , G. H. Cao , Z. A. Xu , S. Y. Li

Resistive, magnetization, torque, specific heat and scanning tunneling microscopy measurements are carried out on the hole heavily doped CsFe$_2$As$_2$ single crystals. A characteristic temperature $T^*\sim13$ K, which is several times…

Superconductivity · Physics 2016-06-29 Huan Yang , Jie Xing , Zengyi Du , Xiong Yang , Hai Lin , Delong Fang , Xiyu Zhu , Hai-Hu Wen

A detailed phenomenology of low energy excitations is a crucial starting point for microscopic understanding of complex materials such as the cuprate high temperature superconductors. Because of its unique momentum-space discrimination,…

Experimental data obtained from thermodynamic measurements in underdoped high temperature superconductors show unusual anomalies in the temperature dependence of the electronic specific heat both in the normal state and at the critical…

Superconductivity · Physics 2009-11-10 I. Tifrea , C. P. Moca

Relationship between the superconducting gap and the pseudogap has been the subject of controversies. In order to clarify this issue, we have studied the superconducting gap and pseudogap of the high-Tc superconductor La2-xSrxCuO4 (x=0.10,…

Strongly Correlated Electrons · Physics 2012-08-15 T. Yoshida , W. Malaeb , S. Ideta , A. Fujimori , D. H. Lu , R. G. Moor , Z. -X. Shen , M. Okawa , T. Kiss , K. Ishizaka , S. Shin , Seiki Komiya , Yoichi Ando , H. Eisaki , S. Uchida

Specific heat has been measured in FeSe single crystals down to 0.414 K under magnetic fields up to 16 T. A sharp specific heat anomaly at about 8.2 K is observed and is related to the superconducting transition. Another jump of specific…

Superconductivity · Physics 2017-08-30 Guan-Yu Chen , Xiyu Zhu , Huan Yang , Hai-Hu Wen

The specific heat of high-purity $\rm Ba_{0.68}K_{0.32}Fe_2As_2$ single crystals with the highest reported superconducting $T_c$ = 38.5 K was studied. The electronic specific heat, $C_p$, below $T_c$ shows two gap features, with $\Delta_1…

Superconductivity · Physics 2010-07-08 P. Popovich , A. V. Boris , O. V. Dolgov , A. A. Golubov , D. L. Sun , C. T. Lin , R. K. Kremer , B. Keimer

We report a systematic study on the electronic structure and superconducting (SC) gaps in electron doped NaFe$_{0.95}$Co$_{0.05}$As superconductor using angle-resolved photoemission spectroscopy. Hole-like Fermi sheets are at the zone…

We present detailed heat capacity measurements for Ba(Fe(1-x)Cox)2As2 and Ba(Fe(1-x)Nix)2As2 single crystals in the vicinity of the superconducting transitions. The specific heat jump at the superconducting transition temperature (Tc),…

Superconductivity · Physics 2015-05-13 Sergey L. Bud'ko , Ni Ni , Paul C. Canfield

We present angle-resolved photoemission spectroscopy (ARPES) data on moderately underdoped La$_{1.855}$Sr$_{0.145}$CuO$_4$ at temperatures below and above the superconducting transition temperature. Unlike previous studies of this material,…

We report the 75As nuclear quadrupole resonance (NQR) and specific heat measurements of the heavily hole-doped superconductor KFe2As2 (Tc = 3.5 K). The spin-lattice relaxation rate 1/T1 in the superconducting state exhibits quite gradual…

LiFeAs is one of the new class of iron superconductors with a bulk onset Tc in the 15-17 K range. We report on the specific heat characterization of single crystal material prepared from self-flux growth techniques with significantly…

Superconductivity · Physics 2015-06-11 J. S. Kim , G. R. Stewart , L. Y. Xing , X. C. Wang , C. Q. Jin

We utilize ultrafast optical measurement to study the quasiparticle relaxation in stoichiometric LiFeAs and nearly optimally doped (BaK)Fe2As2 crystals. According to our temperature-dependent studies of LiFeAs, we have observed…

Recent experiments indicate that the excitation spectrum of the cuprates is characterised, in the superconducting state, by two energy scales: the ``coherence energy'' \Delta_c and the ``pseudogap'' \Delta_p. Here we consider a simple…

Superconductivity · Physics 2009-11-07 J. Quintanilla , B. L. Gyorffy

We report a detailed calorimetric study on single crystals of the 5$d$-transition metal pnictide SrPt2As2 with a superconducting critical temperature $T_c$ $\sim$5K. The peculiar field dependence of the electronic specific heat coefficient…

Low-temperature specific heat (SH) is measured on the 1111-type CaFe_{0.88}Co_{0.12}AsF single crystals under different magnetic fields. A clear SH jump with the height \Delta C/T|_Tc = 10.4 mJ/mol K^2 was observed at the superconducting…

Superconductivity · Physics 2019-08-28 Jianan Chu , Teng Wang , Yonghui Ma , Jiaxin Feng , Lingling Wang , Xuguang Xu , Wei Li , Gang Mu , Xiaoming Xie

Using four different experimental techniques, we performed comprehensive studies of the bulk superconductive properties of single crystals of the nearly optimally doped $Ba_{1-x}K_xFe_2As_2$ ($T_{c} \approx 36\,K$), a typical representative…