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Showing 1 to 20 of 46 for “"superconducting transition temperature"”.
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The effect of manganese doping on the superconducting transition temperature and the upper critical field of tin-molybdenum-sulfide
We have measured the superconducting transition temperature, Tc' and the upper critical field, Hc2 (T), of manganese-doped SnMo6S8 (MnxSn1_xMo6S8)' These samples had reproducible superconducting properties. They were characterized by x-ray powder diffractometry, optical microscopy. electron …
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Experimental observations on some reduced-oxygen Chevrel-phase compounds
… PbMo6Sg, and Cu1.gMo6Sg. Measurements of the temperature dependence of the magnetic susceptibility have been made on these gettered Chevrel compounds, and comparisons have been made between the Pauli susceptibility of gettered and ungettered compounds. The Pauli susceptibility is proportional …
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Temperature dependence of impurity resonances in cuprate superconductors
In conventional superconductors the superconducting gap in the electronic excitation spectrum prevents scattering of low energy electrons. In high temperature superconductors (HTS) an additional gap, the pseudogap, develops well above the superconducting transition temperature Tc. The identity of …
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Visualizing Cooper Pair Formation on the Atomic Scale in High Temperature Superconductors
… in cuprates, one hotly debated issue is the temperature at which Cooper pairs first form. Do pairs form at the critical temperature Tc or do they form at higher temperatures lacking phase rigidity? To answer the question, we have developed new techniques, based on scanning tunneling …
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Hall effect in the superconducting and normal states in detwinned and twinned single crystals of zinc-doped yttrium barium copper oxide
… reversal of the Hall effect for crystals with superconducting transition temperature (T$\rm\sb{c}$) as low as 58.51K. Below the transition temperature, the Hall conductivity followed the C$\sb1$/H+C$\sb2$H law. According to the theory of the Hall effect in the mixed state$\sp{\lbrack …
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Far infared reflectance along the C-axis of the charge stripe superconductor La1.875Ba0.125CuO4.
… along the c-axis of La1.875 Bao.125CU04 at temperatures above(6K) and below(O.5K) the bulk superconducting transition temperature(3K) were performed using a Bruker rapid scan spectrometer and a Martin-Puplett polarizing spectrometer. It was found that when polarized light reflected from a …
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Pressure dependence of superconductivity in amorphous Ni x Zr 100-x alloys
Pressure variations of the superconducting transition temperature Ic of a series of amorphous NixZr 1 OO-x alloys have been studied under quasmydrostatic pressures upto 8 G Pa. For amorphous samples having Ni-concentration less than 40%, i)Tc/dP is positive in sign and it decreases non linearly …
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Pressure dependence of spin fluctuations in metallic glasses Zrâ â Niâ â ,Zrâ â (Nix/Feâ â â -x)â â and /Zrx/feâ â â -x
The superconducting transition temperature Tc of metallic glasses ZrxFelOO-x (x=80, 75), Zr75(NixFelOO-x)25 (x=75, 50, 25), and CU2SZr75 were measured under quasi-hydrostatic pressure up to 8 OPa (80kbar). The volume (pressure) dependence of the electron-phonon coupling parameters Aep for CU25Zr75 …
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Growth, Characterization and Measurement of Epitaxial Sr2RuO4 Thin Films
… by changes in oxygen pressure, substrate temperature, target to substrate distance, and laser fluence. High oxygen pressure, low substrate temperature, large target to substrate distance, and high laser fluence increased the tendency to form the Ru-rich SrRuO3 phase in the film. The second …
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Imaging the two gaps of the high temperature superconductor Pb-Bi₂Sr₂CuO₆₊x
… nature and behavior of electronic states in high temperature superconductors are the center of much debate. The pseudogap state, observed above the superconducting transition temperature Tc, is seen by some as a precursor to the superconducting state. Others view it as a competing phase. Recently, …
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Thermische Tieftemperatureigenschaften von Seltenerd-Übergangsmetall-Borkarbiden
The present work reports on thermal low-temperature properties of rare earth transition metal borocarbides such as specific heat, thermal conductivity and thermopower. The influence of structural disorder, caused by stoichiometric variations and substitutions of the rare earth element or the …
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Superconductivity of thorium hydrides and thorium deuterides
… a high hydrogen to metal atom ratio would be superconducting» we have tested the superconductivity of thorium hydrides and found that Th4 H15 is a superconductor with a transition temperature near 8K, Measurements of the diamagnetic susceptibility of 24 thorium hydride and thorium deuteride …
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Topics in the Theory of High-Temperature Superconductors
… the origin of superconductivity in the hightemperature cuprate superconductors lies in the intriguing properties of the global phase diagram of the cuprate materials. In particular, strongly underdoped cuprates exhibit antiferromagnetic order, whereas moderately underdoped cuprate …
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The anisotropy of the upper critical field of chevrel phase compounds
… planes. At each of a series of field values the superconducting transition temperature oscillated as a function of direction. Since the Hc2 versus T curve is linear in the field region we probed, the shape of the anisotropy in T c at constant H is the same as the anisotropy of the upper critical …
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Studies in Magnetism and Superconductivity under Extreme Pressure
… of materials. High pressure can change the superconducting transition temperature, create new superconductors, change the magnetic state of a material, and induce structural transitions. In Eu metal the strong local-moment magnetism in divalent Eu: 4f<super>7</super>) suppresses …
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Spin fluctuations and high temperature superconductivity in the copper oxides
… correlated copper oxide high temperature superconductors. The spin fluctuation mechanism is first studied within a weak coupling approximation. It is shown that the retarded interaction between quasiparticles on a 2D square lattice induced by the exchange of antiferromagnetic …
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Active control of superconductivity by means of the ferromagnetic exchange interaction
… in the exchange interaction will increase the superconducting transition temperature (Tc) of the heterostructure. Thus by changing the magnetisation of the ferromagnetic regions it is possible to control the exchange interaction in the superconductor and so the superconducting properties of the …
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The doping and magnetic field dependence of the heat capacity of yttrium barium copper oxide superconductors
… magnitude of the fluctuation effects near the superconducting transition temperature is also sharply decreased upon the removal of oxygen and, hence, the transition temperature. This is in stark contrast to what is observed in conventional superconductors when impurities are introduced. In …
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Disorder and Doping in the Oxygenated Electron-doped Superconductor PCCO
… of two parts: the first part deals with the high temperature electron-doped superconductor Pr_(2-x)Ce_(x)CuO_(4-delta); the second part deals with the diluted magnetic semiconductor Ti_(1-x)Co_(x)O_(2-delta). It is not clear why oxygen reduction and cerium doping are necessary to obtain …
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Pairing symmetry, competing orders, and quantum criticality in iron based superconductors via London penetration depth measurements
The temperature dependence of the magnetic penetration depth (λ) has been measured in single crystals of BaFe2As2 that have been driven into superconductivity by several different kinds of dopants, specifically potassium, cobalt, and phosphorous. In (Ba{0.6}K{0.4})Fe2As2 the low temperature …
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