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.

scholarly journals Enhanced process stability for the low temperature sputter deposition of aluminium nitride thin films

2018 ◽  
Vol 5 (6) ◽  
pp. 066412 ◽  
Author(s):  
M Fischeneder ◽  
A Bittner ◽  
M Schneider ◽  
U Schmid
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Sputter Deposition ◽  
Aluminium Nitride ◽  
Process Stability

THE INFLUENCE OF SPUTTERING TIME AND OXYGEN PARTIAL PRESSURE ON ELECTRICAL RESISTIVITY OF Bi:2201 THIN FILMS

2004 ◽  
Vol 18 (14) ◽  
pp. 2085-2090 ◽  
Author(s):  
AUREL POP ◽  
GHEORGHE ILONCA ◽  
ROBERT DELTOUR
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Partial Pressure ◽  
Superconducting State ◽  
Electrical Resistance ◽  
Theoretical Models ◽  
Superconducting Transition ◽  
Partial Pressure Of Oxygen ◽  
Optimal Doping ◽  
Synthesis Conditions

By using different times of sputtering and different value of partial pressure of oxygen in sputtering gas, Bi 2.1 Sr 1.9 CuO y thin films ( Bi :2201) were deposited onto heated single crystal (100) MgO substrates. The temperature dependence of the in-plane resistivity measured on epitaxial c-axis thin films is strongly influenced by the thin films synthesis conditions. Electrical resistivity changes strongly from optimal doping superconducting state to underdoped insulator state with decreasing partial pressure in sputtering gas. The increase of electrical resistance near superconducting transition were analyzed by using some theoretical models.

In situ Sputter Deposition of PbTiO3 Thin Films on Different Substrates: Influence of the Growth Temperature and the Sputtered Lead Flux on the Perovskite Phase Formation

1997 ◽  
Vol 12 (4) ◽  
pp. 997-1007 ◽  
Author(s):  
B. Jaber ◽  
D. Rèmiens ◽  
B. Thierry
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Substrate Temperature ◽  
Phase Formation ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sputter Deposition ◽  
Lead Content ◽  
Substrate Nature

Thin films of lead titanate were prepared in situ using radio-frequency magnetron sputter deposition. The in situ perovskite phase formation has been studied as a function of the substrate temperature, the sputtered lead flux, and the substrate nature. The incident lead flux is controlled by the lead content in the target. An equilibrium zone, i.e., a saturation effect of the lead incorporation, exists where the films are stoichiometric. The temperature at which this zone appears depends on the sputtered lead flux and the substrate type. The growth mechanism is governed by a competition between the arrival rate of Pb and their re-evaporation from the film during the growth. The in situ formation temperature of the perovskite phase increased when the incident Pb flux increased. As a result, PbTiO3 films have been prepared at low temperature with appropriate combination of the substrate temperature and the lead content in the target, i.e., the sputtered lead flux. Since the lead sticking coefficient is very sensitive to the substrate material, the perovskite phase appears at different temperatures, depending on the substrate nature. PbTiO3 films are obtained at 550 °C on Al2O3 and SrTiO3 substrates; on Si/SiO2/Ti/Pt substrates, stoichiometric films are obtained at 440 °C. The structure and the microstructure of the films were examined at various deposition conditions. The substrate temperature strongly influenced the film orientation, and the crystallinity depended on the incident lead flux. High quality thin films (FWHM = 0.2°) are obtained at 550 °C on SrTiO3 substrates. The films deposited at 440 °C on Si/SiO2Ti/Pt show ferroelectric properties. This self-controlling mechanism of the stoichiometric composition allows the growth of ferroelectric films at low temperature, compatible with semi-conductor technologies for the realization of integrated circuits

Effects of High-Energy Ion Irradiation in Bismuth Thin Films at Low Temperature

2003 ◽  
Vol 792 ◽  
Author(s):  
Yasuhiro Chimi ◽  
Norito Ishikawa ◽  
Akihiro Iwase
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Heavy Ions ◽  
Ion Irradiation ◽  
High Energy ◽  
Superconducting Transition ◽  
Abrupt Increase ◽  
Annealing Behavior

ABSTRACTWe have studied high-energy ion irradiation effects in bismuth by measuring the electrical resistivity at low temperature in relation to its structural change. Bismuth thin films (330–520 Å thick) are irradiated below ∼10 K with energetic (150–200-MeV) heavy ions. The resistivity of the specimen is measured in situ below ∼7.2 K during the irradiation. After the irradiation, annealing behavior of the resistivity is observed up to ∼30 K. The temperature dependence of the resistivity during annealing shows an abrupt increase around 20 K, implying re-crystallization of irradiation-induced amorphous regions. We have tried to detect a superconducting transition which may take place as a result of irradiation-induced amorphization. In the range of the measuring temperature down to ∼4.9 K, resistivity decrease due to superconducting transition has not been observed in the temperature dependence of the resistivity after 200-MeV 197Au ion irradiation up to a fluence of 3.1×1012 cm-2.

Structural and electroacoustic studies of AlN thin films during low temperature radio frequency sputter deposition

2001 ◽  
Vol 19 (5) ◽  
pp. 2664-2669 ◽  
Author(s):  
F. Engelmark ◽  
G. F. Iriarte ◽  
I. V. Katardjiev ◽  
M. Ottosson ◽  
P. Muralt ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Radio Frequency ◽  
Sputter Deposition
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