相关论文: Structure and Tc of Y0.8Ca0.2Ba2Cu3O6.92 under Hig…
We performed susceptibility measurements on Y1-yCayBa2Cu3Ox single crystals under high He pressure. For each Ca content various samples with different oxygen contents have been prepared to probe the influence of Ca on Tc(x), dTc/dp(x) and…
In YBa2Cu3Ox, distinct features are found in the pressure dependence of the transition temperature, dTc/dp, and in DeltaCp*Tc, where DeltaCp is the jump in the specific heat at Tc: dTc/dp becomes zero when DeltaCp*Tc is maximal, whereas…
We propose a model for charge transfer mechanism in Y0.8(Ca)0.2Ba2Cu3O6+x to count hole doping of CuO2 planes and x dependence of critical transition temperature T_c. It is assumed the total number of doped holes in the planes is sum of…
Here we study the effect of Ca doping on charge transfer mechanism of polycrystalline YBa2Cu3O7-{\delta} compound. The samples of composition Y1-xCaxBa2Cu3O7-{\delta} (x = 0.00, 0.05, 0.10, 0.20 and 0.30) are synthesized through standard…
We studied Tc of YBa2Cu3Ox (Y123), Y0.89Ca0.11Ba2Cu3Ox (YCa123) and NdBa2Cu3Ox (Nd123) single crystals with various oxygen contents x. Compared to Tc(x) of Y123 the Tc(x) curves of YCa123 are shifted to lower oxygen contents and the maximum…
We performed ac-susceptibility measurements of magnesium diboride powder samples under pure hydrostatic pressures up to 0.4 GPa and under quasi-hydrostatic pressure conditions up to 8 GPa in a helium gas pressure cell and a diamond-anvil…
We apply a method based on a BCS-type approach to the extended Hubbard model to deal with the YBa_2Cu_3O_{7-\delta} superconductor family under pressure. The parameters of the tight-binding band are taken from experiments, and the coupling…
In accordance with a relation between the lattice parameter c and the concentration of holes p, which has been found earlier for the YBa2Cu3O6+d compound, we obtain the p parameter in the same manner for the solid solution Nd1.2Ba1.8Cu3O6+d…
x dependences of Tc in YBa2Cu3O6+x and Y1-b(Ca)bBa2Cu3O6+x (b=0.1 and b=0.2) have been calculated assuming that the net doping of CuO2 layers is a sum of contributions from CuO chains and from substitution of Y3+ by Ca2+. We applied the…
The electron hole concentration p in the CuO2 planes of YBa2Cu3O6+x (YBCO) has been evaluated using the unit cell length in the c-direction together with a simple estimation for p in the chain oxygen ordered phases. The empirical…
Using a diamond anvil cell with nearly hydrostatic helium pressure medium we have significantly extended the superconducting phase diagram Tc(P) of Sc, the lightest of all transition metals. We find that superconductivity is induced in Sc…
A model for charge transfer mechanism in YBa2Cu3O6+x high-Tc cuprate based on critical chain length concept is proposed to account for 60K and 90K plateaus in Tc(x) dependence. It has been shown, when the statistics of CuO chain formation…
A model of charge transfer mechanism from CuO chains to CuO2 planes has been proposed to account for doping of the planes, assuming that only chains containing more than three oxygen atoms can contribute to hole transfer. Only chains with…
High-temperature superconducting cuprates respond to doping with a dome-like dependence of their critical temperature ($T_{\mathrm{c}}$). But the family specific maximum $T_\mathrm{c}$ can be surpassed by application of pressure, a…
Yttrium superhydrides has attracted much attention due to their multiple stoichiometries and excellent superconductivities under high pressure. Especially, YH9 have a Tc of 243 K, which is the second highest Tc among all binary hydrides. It…
The dependence of Tc on nearly hydrostatic pressure has been measured for an isotopically pure (11B) MgB2 sample in a helium-loaded diamond-anvil-cell to nearly 20 GPa. Tc decreases monotonically with pressure from 39.1 K at ambient…
We report a high-pressure study on the heavily electron doped Lix(NH3)yFe2Se2 single crystal by using the cubic anvil cell apparatus. The superconducting transition temperature Tc = 44 K at ambient pressure is first suppressed to below 20 K…
The influence of the hydrostatic pressure P up to 0.95 GPa on the excess conductivity and the pseudogap {\Delta}*(T) in optimally doped YBCO single crystals (T_c = 91.1K at ambient pressure) is investigated by electrical resistivity…
We have measured the pressure sensitivity of Tc in fluorinated HgBa2Ca2Cu3O(8+d) (Hg-1223) ceramic samples with different F contents, applying pressures up to 30 GPa. We obtained that Tc increases with increasing pressure, reaching…
Cuprate HTSCs exhibit a dome-shaped dependence of the superconducting transition temperature on the charge carrier concentration, Tc(p), with a maximum at p = 0.16. Near the composition p = 1/8, a dip in Tc is observed (the "1/8 anomaly"),…