Related papers: Y358 against Y123 structural phase in a Y-based su…
A first-order phase transition is found in the multilayer cuprate superconductor, HgBa$_2$Ca$_4$Cu$_5$O$_y$ (Hg-1245), with a superconducting transition temperature of 108 K, under zero magnetic field. We observed a hysteretic specific heat…
We measured the pressure dependence of in-plane resistivity $\rho_{ab}$ in the recently-discovered iron-based superconductor Ca$_{10}$(Ir$_{4}$As$_{8}$)(Fe$_{2-x}$Ir$_{x}$As$_{2}$)$_{5}$, which shows a unique structural phase transition in…
We have determined the crystal structures and superconducting transition temperatures of La1.48Nd0.4Sr0.12CuO4 under nearly hydrostatic pressures in diamond anvil cells to 5.0 GPa and 19.0 GPa, respectively. Synchrotron x-ray powder…
The electronic spin susceptibility of YBa_2Cu_3O_{6.95} has been measured with high precision up to 24 Tesla with 17O nuclear magnetic resonance. Its temperature dependence can be accounted for by superconducting fluctuations that result in…
Evidence is growing that a second dome of high-$T_\mathrm{c}$ superconductivity can be accessed in the cuprates by increasing the doping beyond the first dome. Here we use \emph{ab initio} methods without invoking any free parameters, such…
The oxygenation process at constant temperature of YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) was systematically investigated in the temperature range from 300 $^o$C to 800 $^o$C. With this purpose, fully deoxygenated powder samples was exposed to…
We report investigation of structural phase transitions in technologically important material sodium niobate as a function of temperature on heating over 300-1075 K. Our high resolution powder neutron diffraction data show variety of…
We discuss a recent resonant ultrasound spectroscopy (RUS) study of YBa$_2$Cu$_3$O$_{6+\delta}$, which infers a line of phase transitions bounding the pseudogap phase and argue that this scenario is not supported by thermodynamic evidence.…
A pivotal ongoing debate about cuprate superconductors (HTS) is the location of the transition temperatures for the superconducting wave function phase coherence and condensation, Tphase and Tcond. This shall elucidate which of two very…
A series of new Sr2-xBaxCuO3+y (0 x 0.6) superconductors were prepared using high-pressure and high-temperature synthesis. A Rietveld refinement based on powder x-ray diffraction confirms that the superconductors crystallize in the…
BaFe2Se3 (Pnma, CsAg2I3-type structure), recently assumed to show superconductivity at ~ 11 K, exhibits a pressure-dependent structural transition to the CsCu2Cl3-type structure (Cmcm space group) around 60 kbar, as evidenced from…
The effect of the 16O-->18O substitution on the superconducting transition temperatures Tc of NaxCoO2.yH2O has been studied for several sets of samples. Each set has two kinds of samples, one with the oxygen sites in the CoO2 layers filled…
The discovery of high-temperature superconductors remains a central challenge in materials science. Hydrogen-rich compounds are among the most promising candidates, as they can exhibit phonon-mediated superconductivity at elevated critical…
Superconductivity is observed in a new nontoxic cuprate system Ga-Ba-Ca-Cu-O, with Tc = 82K for GaBa2Ca5Cu6O14+{\delta} (Ga-1256) and Tc = 116K probably for GaBa2Ca3Cu4O10+{\delta} (Ga-1234) or GaBa2Ca2Cu3O8+{\delta} (Ga-1223),…
In this paper we report an extensive neutron diffraction investigation at high temperature on the BaCe0.80Y0.20O2.9 proton conducting material. Our results precisely define the structural evolution of the compound as a function of…
The temperature ($T$) as a function of pressure ($P$) phase diagram is reported for the cubic Laves phase compound Au$_2$Pb, which was recently proposed to support linearly dispersing "topological" bands, together with conventional…
Current-voltage characteristics of planar junctions formed by an epitaxial c-axis oriented YBa2Cu3O7-x thin film micro-bridge and Ag counter-electrode were measured in the temperature range from 4.2 K to 300 K. A hysteretic behavior related…
The structural features and physical properties of the antiferromagnetic K0.8Fe1.6Se2 (so called K2Fe4Se5 phase) have been studied in the temperature range from 300K up to 600K. Resistivity measurements on both single crystal and…
We report synthesis and properties of superconducting Bi$_2$PdPt, a new member of Bi-Pd based compounds known for their simultaneous existence of topological surfaces states and superconductivity. It crystallizes in a hexagonal structure…
We use ab initio pseudopotential total energy calculations with a plane wave basis set to investigate the structural energetics of various phases of polymorphic NbN. Particular attention is given to its recently discovered superconducting…