27 Result(s)
within
Characterization and Evaluation of Materials
M. Ausloos
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Chapter
Paraconductivity Measurements and Comparative Studies of Fluctuations in BiSrCaCuO, YBaCuo and YBaCuO with Gd Substitution
Information concerning the dimensionality of the superconductive fluctuations in the new high temperature superconductors can be derived from the excess conductivity (or paraconductivity) near the transition t...
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Chapter
Superconductivity Fluctuation Effects on Electrical and Thermal Transport Phenomena. H=0,T>TcI
The shape of the electrical resistance versus temperature curve in the vicinity of a superconductivity transition depends on the amount of superconducting materials (among other things) in the sample. The same...
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Article
Microstructure development in isothermally melt-textured 123–211 composite materials
Microstructures of isothermally melt-textured 123–211 composite materials have been examined during the solidification process from quenched specimens. The distribution of 211 particles, the superconducting 12...
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Article
Non-isovalent metal substitution for bismuth, strontium, calcium, and copper in bi-based 2212 superconducting ceramics
The aim of this paper is to investigate the influence of non-isovalent alkali (Li, Na, K, and Cs) substitution in Bi2Sr2CaCu2O8, in particular on its synthesis conditions and on their resistive and thermopower el...
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Article
Phase Transitions, Patterns and Statistical Mechanics of Front Propagation in a Dynamic Random Impurity Model for Strip, Unusual Trees and Other Geometries
A dynamic random impurity model is studied lor describing the evolution of an advancing interface through a multiphase random medium containing mobile impurities. A short range repulsion between the front and ...
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Chapter
Critical Behavior of the Thermal Conductivity near a Magnetic Phase Transition
The phenomenological Weiss molecular field approximation (MFA) allows one to use the dominant coupling forces between neighbouring spins in order to desribe the production of a spontaneous magnetisation below ...
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Chapter
Effect of Fluctuations on the Thermal Conductivity of High-TC Superconductors
The superconductivity fluctuation contribution kfl to the thermal conductivity of Bi2Sr1.8Ca1.2Cu2O8+y and DyBa2Cu2O7-x polycrystals is extracted from precise experimental data. A crossover from 2D to 3D behavior...
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Chapter
Electrical and Thermal Magneto-Transport in the Mixed State of High Tc-Superconductors
The electrical resistivity, thermoelectric power (or Seebeck effect) and thermal conductivity probe the charge and heat carrier currents caused by external electric and temperature gradients. When a magnetic f...
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Chapter
Electric Field Effects in High-T c Superconductors
The concentration of mobile carriers (electrons and holes) governs the electron transport of any substance. In semiconductors essential electric field effects are prevalent. Only little influence of the electr...
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Chapter
Fluctuation Phenomena in Superconductors
During the first half of this century after the prominent discovery done by Kamerlingh-Onnes, the problem of fluctuations, smearing the superconducting transition, had not even been taken into account: in bulk...
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Article
Magnetotransport Studies of Bi-Based 2212 and 2223 High Critical Temperature Superconductors
When a magnetic field is superimposed on a superconducting sample the electric and temperature gradients allow one to observe phenomena called excess electrical resistivity, excess thermoelectric power, Nernst...
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Article
Studies of Crack Pattern in Two Dimensional Media as Resulting From Ion Beam like or Freezing Destruction
We have numerically studied various models for crack formation in the slow dynamical regime. Two different aspects are presented herein: (i) sputtering with reconstruction and (ii) internal destruction of a po...
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Article
Non Trivial Processes for Obtaining Bi-Based High Tc Superconductors
Dysprosium doped Bi-based 2212 ceramics were synthesized by a melt-texturing growth process in a 1.2T magnetic field, applied perpendicularly to the main axis of a cylindrically shaped sample. The materials we...
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Chapter
Vortex Lattice Melting and Viscosity in Y0.6Dy0.4Ba2Cu3O7−X Superconductor Studied by Electrical Resistivity
Among the scientific problems raised by High Critical Temperature (Tc) Superconductors (HTcS) extensive experimental research has clearly shown the complexity of these perovskite cuprate compounds both because of...
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Chapter and Conference Paper
Vortex Pinning and Dynamics in Perovskite Oxides: Thermal Magneto-Transport in the Mixed State
Vortex arrays have been predicted to exist in type-II superconductors by Abrikosov[1]. They are of interest, not only because of technological reasons, i.e. the possibility of blocking the critical current-decay ...
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Chapter
Electric Field Effects in High-T C Cuprates with Different Bulk and Surface Conductivities
Dependences of T c on hole concentration in YBa2Cu3O7-y and Bi2Sr2CaCu2O8+x cuprates have been calculated in the transverse electric field E in the framework of t...
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Article
Effect of Synthesis Process and Substrate on Electrical and Thermal Transport Properties of Bi-2212
Resistivity, thermoelectric power, and thermal conductivity have been measured for a Bi-2212 system synthesized from a glassy precursor, either with a commercially Al2O3 substrate or with a homemade BaZrO3 substr...
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Article
Two Peak Effect in GMR: A Chemical Effect?
We show that the synthesis conditions have a dramatic influence on the resistivity behavior of calcium and sodium doped LaMnO3. Several samples prepared by lowtemperature techniques exhibit a double-peaked curve ...
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Article
Phase Transition and Pattern of Self-Organized Microstructures in Presence of Mobile Impurities
A growth model starting from a surface and in presence of mobile nonreactive localized impurities has been studied for the statistical physics of the microstructure and the surface roughness through simulation...
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Chapter
Field Dependent Exponents of Superconducting Fluctuations
The electrical resistivity of a quasi monocrystalline Bi 2 Sr 2 CaCu 2 O y sample ...
