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Related papers: Specific heat in KFe2As2 in zero and applied magne…

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The recently discovered LaFe2As2 superconducting compound, member of the 122 family of iron pnictide superconductors, becomes superconducting below Tc=13K, yet its nominal doping apparently places it in the extreme overdoped limit, where…

Superconductivity · Physics 2025-02-18 Ilaria Pallecchi , Akira Iyo , Hiraku Ogino , Marco Affronte , Marina Putti

Electron-doped Sr(Co{1-x}Ni{x})2As2 single crystals with compositions x = 0 to 0.9 were grown out of self-flux and SrNi2As2 single crystals out of Bi flux. The crystals were characterized using single-crystal x-ray diffraction (XRD),…

Strongly Correlated Electrons · Physics 2019-10-09 N. S. Sangeetha , L. L. Wang , A. V. Smirnov , V. Smetana , A. -V. Mudring , D. D. Johnson , M. A. Tanatar , R. Prozorov , D. C. Johnston

EuC$_2$ is a ferromagnet with a Curie-temperature of $T_C \simeq 15\,$K. It is semiconducting with the particularity that the resistivity drops by about 5 orders of magnitude on cooling through $T_C$, which is therefore called a…

Materials Science · Physics 2011-12-01 O. Heyer , P. Link , D. Wandner , U. Ruschewitz , T. Lorenz

Specific heat for single crystalline samples of Ce1-xLaxOs4Sb12 at zero-field and magnetic fields to 14 T is reported. Our results confirm enhanced value of the electronic specific heat coefficient in the paramagnetic state. They provide…

Strongly Correlated Electrons · Physics 2013-05-29 C. R. Rotundu , B. Andraka

We report the effect of applied pressures on magnetic and superconducting order in single crystals of the aliovalent La-doped iron pnictide material Ca$_{1-x}$La$_{x}$Fe$_{2}$As$_{2}$. Using electrical transport, elastic neutron scattering…

The normal-state in-plane resistivity below the zero-field superconducting transition temperature $T_c$ and the upper critical field Hc2 were measured by suppressing superconductivity in pulsed magnetic fields for K0.70Fe1.46Se1.85Te0.15.…

Superconductivity · Physics 2015-01-07 Kefeng Wang , Hyejin Ryu , Erik Kampert , M. Uhlarz , J. Warren , J. Wosnitza , C. Petrovic

75As-zero-field nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements are performed on CaFe2As2 under pressure. At P = 4.7 and 10.8 kbar, the temperature dependences of nuclear-spin-lattice relaxation rate…

Superconductivity · Physics 2015-05-18 S. Kawasaki , T. Tabuchi , X. F. Wang , X. H. Chen , Guo-qing Zheng

We present experimental results for the in-plane resistivity of the electron-doped cuprate superconductor $La_{2-x}Ce_xCuO_4$ above its transition temperature $T_c$ as a function of Ce doping x and temperature. For the doping x between 0.11…

Strongly Correlated Electrons · Physics 2018-12-19 Tarapada Sarkar , Richard L. Greene , S. Das Sarma

We study the temperature and pressure dependence of the structural and electronic properties of the iron pnictide superconductor BaFe2As2. We use density functional theory based Born-Oppenheimer molecular dynamics simulations to investigate…

Strongly Correlated Electrons · Physics 2013-08-06 Steffen Backes , Harald O. Jeschke

Single-crystalline KFe2As2 and CaT2As2 (T = Fe, Co, Ni, Cu) are synthesized and investigated by resistivity, susceptibility and optical spectroscopy. It is found that CaCu2As2 exhibits a similar transition to the lattice abrupt collapse…

Superconductivity · Physics 2015-06-11 B. Cheng , B. F. Hu , R. Y. Chen , G. Xu , P. Zheng , J. L. Luo , N. L. Wang

Superconductivity has been first observed in TlNi$_2$Se$_2$ at T$_C$=3.7 K and appears to involve heavy electrons with an effective mass $m^*$=14$\sim$20 $m_b$, as inferred from the normal state electronic specific heat and the upper…

Superconductivity · Physics 2013-11-20 Hangdong Wang , Chiheng Dong , Qianhui Mao , Rajwali Khan , Xi Zhou , Zhenxia Li , Bin Chen , Jinhu Yang , Qiping Su , Minghu Fang

Superconductivity was recently observed in the iron-arsenic-based compounds with a superconducting transition temperature (Tc) as high as 56K [1-7], naturally raising comparisons with the high Tc copper oxides. The copper oxides have…

Superconductivity · Physics 2009-11-13 H. Q. Yuan , J. Singleton , F. F. Balakirev , S. A. Baily , G. F. Chen , J. L. Luo , N. L. Wang

Specific heat $C(T)$ measurements were made on single crystals of the superconducting filled skutterudite series Pr(Os$_{1-x}$Ru$_x$)$_4$Sb$_{12}$ down to 0.6 K. Crystalline electric field fits in the normal state produced parameters which…

Superconductivity · Physics 2009-11-10 N. A. Frederick , T. A. Sayles , M. B. Maple

A technique for measuring the electrical resistivity and absolute thermopower is presented for pressures up to 30 GPa, temperatures down to 25 mK and magnetic fields up to 10 T. With the examples of CeCu2Ge2 and CeCu2Si2 we focus on the…

Strongly Correlated Electrons · Physics 2007-05-23 D. Jaccard , E. Vargoz , K. Alami-Yadri , H. Wilhelm

We report on structural, magnetic, conductivity, and thermodynamic studies of FeSe$_{0.5}$Te$_{0.5}$ single crystals grown by self-flux and Bridgman methods. The samples were prepared from starting materials of different purity at various…

Superconductivity · Physics 2011-03-25 V. Tsurkan , J. Deisenhofer , A. Günther , Ch. Kant , H. -A. Krug von Nidda , F. Schrettle , A. Loidl

In unconventional superconductors, it is generally believed that understanding the physical properties of the normal state is a pre-requisite for understanding the superconductivity mechanism. In conventional superconductors like niobium or…

We performed $^{75}$As NMR studies on two overdoped high-quality Ba$_{1-x}$K$_{x}$Fe$_2$As$_2$ (x=0.7 and 1.0) single crystals. In the normal states, we found a dramatic increase of the spin-lattice relaxation ($1/^{75}T_1$) from the x=0.7…

Superconductivity · Physics 2010-01-13 S. W. Zhang , L. Ma , Y. D. Hou , J. S. Zhang , T. L. Xia , G. F. Chen , J. P. Hu , G. M. Luke , W. Yu

We present new specific heat data for Nb3Sn, a well-known technically applied superconductor with a critical temperature T_c ~ 18 K, in the temperature range from 1.2 to 200 K in zero magnetic field, and from 1.5 to 22 K in fields H <= 16…

Superconductivity · Physics 2009-11-10 V. Guritanu , W. Goldacker , F. Bouquet , Y. Wang , R. Lortz , G. Goll , A. Junod

The zero-field specific heat of LiFeAs was measured on several single crystals selected from a bulk sample. A sharp Delta Cp/Tc anomaly of approximately 20 mJ/(mole x K^2) was observed. The value appears to be between those of…

Superconductivity · Physics 2011-05-06 F. Wei , F. Chen , K. Sasmal , B. Lv , Z. J. Tang , Y. Y. Xue , A. M. Guloy , C. W. Chu

We present a detailed study of the quasiparticle contribution to the low-temperature specific heat of an extreme type-II superconductor at high magnetic fields. Within a T-matrix approximation for the self-energies in the mixed state of a…

Superconductivity · Physics 2009-11-10 A. L. Carr , J. J. Trafton , S. Dukan , Z. Tesanovic