DOPING AND TEMPERATURE DEPENDENCE OF SUPERFLUID DENSITY IN KINETIC ENERGY DRIVEN CUPRATE SUPERCONDUCTORS

2010 ◽  
Vol 24 (29) ◽  
pp. 2845-2854
Author(s):  
ZHEYU HUANG ◽  
HUAISONG ZHAO ◽  
SHIPING FENG
Keyword(s):  
Transition Temperature ◽  
Kinetic Energy ◽  
Temperature Dependence ◽  
Low Temperatures ◽  
Cuprate Superconductors ◽  
Superfluid Density ◽  
Linear Temperature Dependence ◽  
Superconducting Transition ◽  
Zero Temperature ◽  
Linear Temperature

Within the kinetic energy driven superconducting mechanism, the doping and temperature dependence of the superfluid density in cuprate superconductors is studied throughout the superconducting dome. It is shown that the superfluid density shows a crossover from the linear temperature dependence at low temperatures to a nonlinear one in the extremely low temperatures. In analogy to the dome-like shape of the doping dependent superconducting transition temperature, the maximal zero-temperature superfluid density occurs around the critical doping δ ≈ 0.195, and then decreases in both lower doped and higher doped regimes.

scholarly journals INTERPLAY BETWEEN SINGLE PARTICLE COHERENCE AND KINETIC ENERGY DRIVEN SUPERCONDUCTIVITY IN DOPED CUPRATES

2004 ◽  
Vol 18 (17) ◽  
pp. 895-907 ◽  
Author(s):  
TIANXING MA ◽  
HUAIMING GUO ◽  
SHIPING FENG
Keyword(s):  
Transition Temperature ◽  
Kinetic Energy ◽  
Single Particle ◽  
Superconducting Transition Temperature ◽  
Spin Structure ◽  
Cuprate Superconductors ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Superconducting Transition ◽  
Dynamical Spin

Within the kinetic energy driven superconducting mechanism, the interplay between the single particle coherence and superconducting instability in doped cuprates is studied. The superconducting transition temperature increases with increasing doping in the underdoped regime, and reaches a maximum in the optimal doping, then decreases in the overdoped regime, however, the values of this superconducting transition temperature in the whole superconducting range are suppressed to low temperature due to the single particle coherence. Within this superconducting mechanism, we calculate the dynamical spin structure factor of cuprate superconductors, and reproduce all main features of inelastic neutron scattering experiments in the superconducting-state.

ANALYSIS OF MAGNETIC CRITICAL FIELDS IN IRON-BASED SmFeAsO0.85 HIGH-Tc SUPERCONDUCTOR

2011 ◽  
Vol 25 (24) ◽  
pp. 1939-1948 ◽  
Author(s):  
DAWOOD AHMAD ◽  
TAE KWON SONG ◽  
IN SUK PARK ◽  
G. C. KIM ◽  
ZHI-AN REN ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Low Temperatures ◽  
Irreversibility Line ◽  
Linear Temperature Dependence ◽  
Critical Fields ◽  
Linear Temperature ◽  
High Tc ◽  
High Tc Superconductor ◽  
Pressure Synthesis ◽  
Iron Based

The magnetic properties of the newly discovered iron-oxypnictide SmFeAsO 0.85 high-Tc superconductor with a Tc of around 55 K were investigated. Bulk SmFeAsO 0.85 was prepared by a method for high-pressure synthesis. The lower critical field H c1 was estimated from the magnetization at low fields; H c1 (0) was measured to be 212 Oe. A linear temperature dependence instead of saturation at low temperatures in H c1 (T) revealed unconventional superconductivity with a nodal gap structure in our SmFeAsO 0.85 superconductor. The results showed that the well-known secondary peak in the temperature dependence of the critical current density Jc is absent in the SmFeAsO 0.85 high-Tc superconductor. The irreversibility line B irr was fitted well by the power law dependence (1 - T/Tc)n with n ~ 1.5. This is indicative of the flux creep phenomena in the SmFeAsO 0.85 high-Tc superconductor. In addition, within the range of measurement temperatures in this study, no crossover was observed in the temperature dependence of the irreversibility line B irr which may be due to low anisotropy in our SmFeAsO 0.85 superconductor.

Electron Irradiation of YBa2Cu3O7 at low Temperatures

1987 ◽  
Vol 99 ◽  
Author(s):  
B. Stritzker ◽  
W. Zander ◽  
F. Dworschak ◽  
U. Poppe ◽  
K. Fischer
Keyword(s):  
Transition Temperature ◽  
Electron Irradiation ◽  
Normal State ◽  
Low Temperatures ◽  
Superconducting Transition Temperature ◽  
Superconducting Transition ◽  
Radiation Induced ◽  
State Resistance ◽  
Normal State Resistance

ABSTRACTBulk samples of YBa2Cu3O7−x have been homogenously irradiated with 3 MeV electrons at temperatures below 20 K. Whereas the superconducting transition temperature, Tc, drops dramatically with increasing dose the width of the transition remains unchanged (Δ Tc ≤ 1.5 K). The normal state resistance at 100 K increases substantially during the electron irradiation. Several irreproducible experiments can be interpreted with a radiation induced, unstable increase of Tc.

Processing Path and The Evolution of Crystallinity in Rapidly Solidified Glassy Alloys

1994 ◽  
Vol 362 ◽  
Author(s):  
M. A. Otooni
Keyword(s):  
Transition Temperature ◽  
Thermomechanical Properties ◽  
Relaxation Processes ◽  
Linear Temperature Dependence ◽  
Linear Temperature ◽  
Glassy Alloys ◽  
Atomic Transport ◽  
The Subject ◽  
Rapidly Solidified ◽  
Selection Of

AbstractAtomic transport properties in rapidly solidified glassy alloys are not fully understood in spite of much experimental data on the subject. Nevertheless, a thorough understanding of these properties is of fundamental importance when studying the practical limits of the application of rapidly solidified glassy alloys.Several attempts are made in this paper to explain our experimental results on the mechanical flow properties near the transition temperature, Tr. These results are interpreted in the context of possible operating mechanisms such as diffusion and/or relaxation processes. Some inferences have been made on the nature of viscosity and its fluctuation near the transition temperature. The linear temperature dependence of the viscosity near the transition temperature is explained by invoking the free-volume concept for the viscosity of the glassy alloys.These results are used to provide appropriate data for the selection of feasible processing paths which will produce alloys with advanced thermomechanical properties.

NANOSCOPIC PHASE SEPARATION AND THE UNIVERSAL TRANSPORT AND MAGNETIC PROPERTIES OF HIGH Tc SUPERCONDUCTORS

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3528-3531
Author(s):  
J. JUNG ◽  
H. YAN ◽  
H. DARHMAOUI ◽  
M. ABDELHADI
Keyword(s):  
Magnetic Properties ◽  
Phase Separation ◽  
Temperature Dependence ◽  
Current Density ◽  
Low Temperatures ◽  
Energy Barrier ◽  
Vortex Motion ◽  
Superfluid Density ◽  
High Tc Superconductors ◽  
High Tc

We have found the correlation between nanoscopic phase separation in the copper-oxygen planes of YBCO and TlBCCO and the transport and magnetic properties of these materials in the a-b planes such as: the temperature dependence of the critical current density Jc( T ), the temperature dependence of the superfluid density ns( T )∝1/λ2( T ) at low temperatures, the temperature dependence of the normalized logarithmic relaxation rate S(T), and the dependence of the effective energy barrier against vortex motion on the current density Ueff( J ). These properties are controlled by the ratio of the amount of an underdoped filamentary phase to that of an optimally doped one.

Sign in / Sign up

Export Citation Format

Share Document