Improvement in the width of superconducting transition ΔTcof Nb3Ge by small mechanical shock

1981 ◽  
Vol 39 (1) ◽  
pp. 113-115 ◽  
Author(s):  
Takumi Watanabe ◽  
Kōzō Obara ◽  
Tetsuya Ōgushi ◽  
Tadashi Numata ◽  
Takeshi Anayama
Keyword(s):  
Mechanical Shock ◽  
Superconducting Transition ◽  
Width Of Superconducting Transition

Resistive Width of Superconducting Transition in Titanium Nitride Thin Film

2011 ◽  
Vol 6 (2) ◽  
pp. 50-56
Author(s):  
Svetlana V. Postolova ◽  
Alexey Yu. Mironov ◽  
Tatyana I. Baturina
Keyword(s):  
Transition Temperature ◽  
Titanium Nitride ◽  
Electron Interaction ◽  
Nitride Film ◽  
Superconducting Transition ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Superconducting Fluctuations ◽  
Width Of Superconducting Transition ◽  
Titanium Nitride Film

The transition to the superconducting state of the ultrathin (5 nm thick) titanium nitride film was studied. It is found that the nonmonotonic temperature dependence of the resistance, R(T), is a consequence of competition between the contributions to conductivity from quantum corrections stemming from the electron-electron interaction in the diffusion and Cooper channels. It is shown that the appreciable decrease in the resistance at T > Tc (Tc is the superconducting transition temperature) results from the superconducting fluctuations. We present the results of the analysis of low-temperature (T < Tc ) current-voltage characteristics V(I). It is found that they follow the power-law behavior V∝ I α(T) , with α(T) increasing rapidly with the decreasing temperature. The Berezinskii-Kosterlitz-Thouless transition temperature, TBKT, and width of the superconducting transition ∆T = Tc − TБКТ were determined

Scaling of Resistivities in MgB2

2006 ◽  
Vol 47 ◽  
pp. 113-117
Author(s):  
Petr Vašek
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Critical Temperature ◽  
External Magnetic Field ◽  
Transport Current ◽  
Zero Magnetic Field ◽  
Superconducting Transition ◽  
Hall Voltage ◽  
Transition Range ◽  
Width Of Superconducting Transition

Longitudinal and transverse voltages have been measured on thin films of MgB2 with different width of superconducting transition range. The study has been performed in zero and nonzero external magnetic fields. The non-zero transverse voltage has been observed in close vicinity of the critical temperature in zero external magnetic field while far enough from Tc this voltage has been zero. In magnetic field it merges into transverse voltage which is an even function with respect to the direction of the field. Usual Hall voltage starts to appear with increasing magnetic field. At the highest field the even voltage disappears and only the Hall voltage is measurable i.e. the transverse even voltage is suppressed with increasing magnetic field and increasing transport current as well. New scaling between transverse and longitudinal resistivities has been observed in the form ρxy~dρxx/dT . This correlation is valid not only in the zero magnetic field but also in nonzero magnetic field where transverse even voltage can be detected. Several models trying to explain observed results are discussed. The most promising seems to be guided motion of the vortices.

Measured Width of Superconducting Transition: Quantitative Probe of Macroscopic Inhomogeneities.

1984 ◽  
Vol 53 (27) ◽  
pp. 2593-2593
Author(s):  
G. E. Zwicknagl ◽  
J. W. Wilkins
Keyword(s):  
Superconducting Transition ◽  
Width Of Superconducting Transition

Measured Width of Superconducting Transition: Quantitative Probe of Macroscopic Inhomogeneities

1984 ◽  
Vol 53 (13) ◽  
pp. 1276-1279 ◽  
Author(s):  
G. E. Zwicknagl ◽  
J. W. Wilkins
Keyword(s):  
Superconducting Transition ◽  
Width Of Superconducting Transition

Microcalorimeters for X-Ray Spectroscopy

1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  
Keyword(s):  
High Resolution ◽  
High Efficiency ◽  
Thermal Response ◽  
Low Noise ◽  
High Resolution Spectroscopy ◽  
Superconducting Transition ◽  
Sapphire Substrates ◽  
Laboratory Plasmas ◽  
Adiabatic Demagnetization ◽  
Theoretical Predictions

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.

Observation by HVEM of the martensite transformation and the superconducting transition in Nb3Sn

1988 ◽  
Vol 46 ◽  
pp. 788-789
Author(s):  
M. A. Kirk ◽  
M. C. Baker ◽  
B. J. Kestel ◽  
H. W. Weber
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Superconducting State ◽  
Martensite Transformation ◽  
Sputter Deposition ◽  
Diffusion Reaction ◽  
Solute Diffusion ◽  
Superconducting Transition ◽  
Twin Boundaries ◽  
Martensite Structure

It is well known that a number of compound superconductors with the A15 structure undergo a martensite transformation when cooled to the superconducting state. Nb3Sn is one of those compounds that transforms, at least partially, from a cubic to tetragonal structure near 43 K. To our knowledge this transformation in Nb3Sn has not been studied by TEM. In fact, the only low temperature TEM study of an A15 material, V3Si, was performed by Goringe and Valdre over 20 years ago. They found the martensite structure in some foil areas at temperatures between 11 and 29 K, accompanied by faults that consisted of coherent twin boundaries on {110} planes. In pursuing our studies of irradiation defects in superconductors, we are the first to observe by TEM a similar martensite structure in Nb3Sn.Samples of Nb3Sn suitable for TEM studies have been produced by both a liquid solute diffusion reaction and by sputter deposition of thin films.

INCREASED RESISTANCE BELOW THE SUPERCONDUCTING TRANSITION IN DISCONTINUOUS FILMS OF (SN)x AND INDIUM

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-448-C6-450 ◽  
Author(s):  
M. W. Young ◽  
J. M.D. Thomas ◽  
C. J. Adkins ◽  
J. W. Tate
Keyword(s):  
Superconducting Transition

Xenon Trioxide Adducts of O-Donor Ligands; [(CH3)2CO]3XeO3, [(CH3)2SO]3(XeO3)2, (C5H5NO)3(XeO3)2, and [(C6H5)3PO]2XeO3

2018 ◽  
Author(s):  
Katherine Marczenko ◽  
James Goettel ◽  
Gary Schrobilgen
Keyword(s):  
Room Temperature ◽  
Triphenylphosphine Oxide ◽  
Donor Ligands ◽  
Mechanical Shock ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Coordination ◽  
Xenon Trioxide ◽  
Distorted Octahedra ◽  
Coordination Spheres

Oxygen coordination to the Xe(VI) atom of XeO<sub>3</sub> was observed in its adducts with triphenylphosphine oxide, dimethylsulfoxide, pyridine-N-oxide, and acetone. The crystalline adducts were characterized by low-temperature, single-crystal X-ray diffraction and Raman spectroscopy. Unlike solid XeO<sub>3</sub>, which detonates when mechanically or thermally shocked, the solid [(C<sub>6</sub>H<sub>5</sub>)<sub>3</sub>PO]<sub>2</sub>XeO<sub>3</sub>, [(CH<sub>3</sub>)<sub>2</sub>SO]<sub>3</sub>(XeO<sub>3</sub>)<sub>2</sub>,<sub> </sub>and (C<sub>5</sub>H<sub>5</sub>NO)<sub>3</sub>(XeO<sub>3</sub>)<sub>2</sub> adducts are insensitive to mechanical shock, but undergo rapid deflagration when ignited by a flame. Both [(C<sub>6</sub>H<sub>5</sub>)<sub>3</sub>PO]<sub>2</sub>XeO<sub>3 </sub>and (C<sub>5</sub>H<sub>5</sub>NO)<sub>3</sub>(XeO<sub>3</sub>)<sub>2</sub> are air-stable whereas [(CH<sub>3</sub>)<sub>2</sub>SO]<sub>3</sub>(XeO<sub>3</sub>)<sub>2</sub> slowly decomposes over several days and [(CH<sub>3</sub>)<sub>2</sub>CO]<sub>3</sub>XeO<sub>3</sub> undergoes adduct dissociation at room temperature. The xenon coordination sphere of [(C<sub>6</sub>H<sub>5</sub>)<sub>3</sub>PO]<sub>2</sub>XeO<sub>3</sub> is a distorted square pyramid which provides the first example of a five-coordinate XeO<sub>3</sub> adduct. The xenon coordination spheres of the remaining adducts are distorted octahedra comprised of three Xe---O secondary contacts that are approximately trans to the primary Xe–O bonds of XeO<sub>3</sub>. Quantum-chemical calculations were used to assess the Xe---O adduct bonds, which are predominantly electrostatic σ-hole bonds between the nucleophilic oxygen atoms of the bases and the σ-holes of the xenon atoms.

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