Related papers: A second phase transition and superconductivity in…
Temperature dependent electrical resistivity, crystal structure and heat capacity measurements reveal a resistivity drop and metal to semiconductor transition corresponding to first order structural phase transition near 400 K in Ca3Co4O9.…
In order to understand the origin of high-temperature superconductivity in copper oxides, we must understand the normal state from which it emerges. Here, we examine the evolution of the normal state electronic excitations with temperature…
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…
Here we report an unconventional magnetic and transport phenomenon in a layered cobalt oxide, NaxCoO2. Only for x = 0.75, a magnetic transition of the second order was clearly detected at Tm ~ 22 K where an apparent specific-heat jump, an…
A superconducting transition in the temperature dependence of the ab-plane resistivity of underdoped YBa_2Cu_3O_{6+x} crystals in the range T_c<30 K has been investigated. Unlike the case of samples with the optimal level of doping, the…
We report appearance of superconductivity at 5K in NdO0.5F0.5BiS2 and supplement the discovery [1] of the same in layered sulfide based ZrCuSiAs type compounds. The bulk polycrystalline compound is synthesized by conventional solid state…
The layered transition metal dichalcogenide compounds 1T-TaS2 and 4H-TaS2 are well known for their exotic properties, which include charge density wave, superconductivity, Mott transition, etc., and lately quantum spin liquid. Here, we…
The superconducting transition temperatures of high-Tc compounds based on copper, iron, ruthenium and certain organic molecules are discovered to be dependent on bond lengths, ionic valences, and Coulomb coupling between electronic bands in…
We synthesized Nax(H3O)zCoO2yH2O samples with various Na/H3O ratios but with the constant Co valence of s = +3.40, and measured their magnetic properties to draw phase diagrams of the system. The superconductivity is very sensitive to the…
We studied the specific heat and thermal conductivity of the spin-triplet superconductor Sr2RuO4 at low temperatures and under oriented magnetic fields H. We resolved a double peak structure of the superconducting transition under magnetic…
The ongoing search for new superconductors has recently yielded a new family of oxypnictides composed of alternating La_2O_{2-x}F_x and Fe_2As_2 layers [1-4] with transition temperatures T_c of 25-28 K, which can be raised to 40-43 K by…
Resistivity and ac magnetic susceptibility measurements on Ba2Sn3Sb6 and SrSn3Sb4 indicate that these Zintl compounds display a transition to a superconducting phase at Tc = 3.9 K. The Meissner effect was observed for Ba2Sn3Sb6 under an…
The newly discovered BiS$_2$-based LaO$_{1-x}$F$_{x}$BiS$_2$ ($x$=0.5) becomes superconductive at $T_c$=2.5 K. Electrical resistivity and magnetization measurements are performed under pressure to determine the pressure dependence of the…
A brief overview of changes in the superconducting transition temperature under pressure and evolution of specific heat capacity jump at Tc for two related families of iron - based superconductors, Ba{1-x}KxFe2As2 (0.2 < x < 1.0) and…
We performed high-pressure transport measurements on high-quality single crystals of KOs2O6, a beta-pyrochlore superconductor. While the resistivity at high temperatures might approach saturation, there is no sign of saturation at low…
The normal state and superconducting properties are investigated in the phase diagram of K_xSr_{1-x}Fe_2As_2 for 0<x<1. The ground state upper critical field, H_{c2}(0), is extrapolated from magnetic field dependent resistivity…
At ambient pressure CaFe2As2 has been found to undergo a first order phase transition from a high temperature, tetragonal phase to a low temperature orthorhombic / antiferromagnetic phase upon cooling through T ~ 170 K. With the application…
We report the observation of superconductivity in high-quality Cd$_2$Re$_2$O$_7$ single crystals with room-temperature pyrochlore structure. Resistivity and ac susceptibility measurements establish an onset transition temperature…
We first show some properties such as smoothness and monotone decreasingness of the solution to the BCS-Bogoliubov gap equation for superconductivity. Moreover we give the behavior of the solution with respect to the temperature near the…
The experimental determination of the superconducting transition requires the observation of the emergence of zero-resistance and perfect diamagnetism state. Based on the close relationship between superconducting transition temperature…