Related papers: Upper critical field from normal state fluctuation…
We measure magnetotransport of F doped SmFeAsO samples up to 28T and we extract the upper critical fields, using different criteria. In order to circumvent the problem of criterion-dependence Hc2 values, we suggest a thermodynamic…
The out-of-plane resistance and the resistive upper critical field of BSCCO-2212 single crystals with Tc=91-93 K have been measured in magnetic fields up to 50 T over a wide temperature range. The results are characterised by a positive…
The orbital upper critical field $H_{c2} $ is evaluated for isotropic materials with arbitrary transport and pair-breaking scattering rates. It is shown that unlike transport scattering which enhances $H_{c2} $, the pair breaking suppresses…
The temperature, doping and field dependences of the magnetoresistance (MR) in Pr_(2-x)Ce_(x)CuO_(4-delta) films are reported. We distinguish between orbital MR, found when the magnetic field is applied perpendicular to the ab planes, and…
We present resistivity measurements of the upper critical field (H$_{c2}$) phase diagram as a function of temperature (T) for Nd$_{1.85}$Ce$_{0.15}$CuO$_{4+\delta}$/SrTiO$_3$ single crystal films with different degree of disorder ($\delta$)…
The current dependence of the excess conductivity is measured up to $\simeq 3 T_c$ for a Bi$_2$Sr$_2$CuO$_{6+\delta}$ thin film, as a function of doping. It is found to be anomalously sensitive to the transport current and to behave as a…
We report on magnetization measurements performed on a single crystal of Bi{2+x}Sr{2-x}CuO{6+\delta} with Tc\sim7 K for H||c-axis. The isofield M(T) curves show a large reversible region, with a pronounced rounding effect as M approaches…
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 present the resistively-determined upper critical field H^{\rho}_{c2}(T) and the irreversibility lines H^{\rho}_{irr}(T) of various high-T_c cuprates, deduced from measurements in 61-T pulsed magnetic fields applied parallel to the…
To elucidate the pseudogap phase diagram including the overdoped state of high transition temperature (high-$T_c$) cuprates, we must understand the origin of the positive out-of-plane magnetoconductivity (MC) observed in these compounds.…
The effect of the magnetic field on the critical behavior of Sr0:9La0:1CuO2 is explored in terms of reversible magnetization data. As the correlation length transverse to the magnetic field Hi,applied along the i-axis, cannot grow beyond…
The temperature and angular dependence of the upper critical field (Hc2) is reported for cobalt-doped SrFe2As2 epitaxial films between Tc and 0.5 K in pulsed magnetic fields up to 50 T. For H parallel c, Hc2 is close to a linear function of…
A large positive magnetoresistivity (up to tens of percents) is observed in both underdoped and overdoped superconducting La2-xSrxCuO4 epitaxial thin films at temperatures far above the superconducting critical temperature Tc. For the…
We study angular-dependent magnetoresistance in a low $T_c$ layered cuprate Bi$_{2.15}$Sr$_{1.9}$CuO$_{6+\delta}$. The low $T_c$ ~ 4 K allows complete suppression of superconductivity by modest magnetic fields and facilitate accurate…
Elastic tunneling is used as a powerful direct tool to determine the upper critical field $H_{c2}(T)$ in the high-$T_c$ oxide Ba$_{1-x}$K$_x$BiO$_3$. The temperature dependence of $H_{c2}$ inferred from the tunneling follows the…
The upper critical field Hc2(T) of sintered pellets of the recently discovered MgB_2 superconductor was investigated in magnetic fields up to 16 T. The upper critical field of the major fraction of the investigated sample was determined…
In the light of the recently discussed mechanism for suppression of superconductivity in multi-orbital systems called inter-orbital effect, here we extend our analysis of the upper critical field in Sr$_2$RuO$_4$ now under strain. We show…
Critical fields of four MgB2 thin films with a normal state resistivity ranging from 5 to 50 mWcm and Tc from 29.5 to 38.8 K were measured up to 28 T. Hc2(T) curves present a linear behavior towards low temperatures. Very high critical…
Magnetotransport measurements are presented on polycrystalline MgB2 samples. The resistive upper critical magnetic field reveals a temperature dependence with a positive curvature from Tc = 39.3 K down to about 20 K, then changes to a…
We study the origin of broadening of superconducting transition in sputtered Nb films. From simultaneous tunneling and transport measurements we conclude that the upper critical field Hc2 always corresponds to the bottom of transition R~0,…