scholarly journals An easily understandable explanation of the possible enhancement mechanism of the high temperature superconductivity of oxides proposed by the new frames in physics and the first report of our experimental studies on BiPbSrCaCu-O system.

1988 ◽  
Vol 35 (5) ◽  
pp. 401-404
Author(s):  
Shuichi Iida ◽  
Toshiharu Mitsui ◽  
Kiyoshi Abe ◽  
Naomi Matsubara
Keyword(s):  
High Temperature ◽  
High Temperature Superconductivity ◽  
Experimental Studies ◽  
First Report ◽  
Enhancement Mechanism

scholarly journals High-temperature superconductivity on the verge of a structural instability in lanthanum superhydride

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dan Sun ◽  
Vasily S. Minkov ◽  
Shirin Mozaffari ◽  
Ying Sun ◽  
Yanming Ma ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperature Superconductivity ◽  
Experimental Studies ◽  
Structural Instability ◽  
High Symmetry ◽  
Superconducting Transition ◽  
Metallic Hydrogen ◽  
Key Factors ◽  
Structural Distortions ◽  
The 1960S

AbstractThe possibility of high, room-temperature superconductivity was predicted for metallic hydrogen in the 1960s. However, metallization and superconductivity of hydrogen are yet to be unambiguously demonstrated and may require pressures as high as 5 million atmospheres. Rare earth based “superhydrides”, such as LaH10, can be considered as a close approximation of metallic hydrogen even though they form at moderately lower pressures. In superhydrides the predominance of H-H metallic bonds and high superconducting transition temperatures bear the hallmarks of metallic hydrogen. Still, experimental studies revealing the key factors controlling their superconductivity are scarce. Here, we report the pressure and magnetic field dependence of the superconducting order observed in LaH10. We determine that the high-symmetry high-temperature superconducting Fm-3m phase of LaH10 can be stabilized at substantially lower pressures than previously thought. We find a remarkable correlation between superconductivity and a structural instability indicating that lattice vibrations, responsible for the monoclinic structural distortions in LaH10, strongly affect the superconducting coupling.

scholarly journals EXPERIMENTAL STUDY OF THE SUPERCONDUCTING MICROSTRIP ANTENNA AS A PROTECTIVE DEVICE OF THE RECEIVER FROM ELECTROMAGNETIC DAMAGE

2017 ◽  
Vol 5 ◽  
pp. 73-88
Author(s):  
Oleksandr Fyk ◽  
Dmutro Kucher ◽  
Roman Gonchar
Keyword(s):  
High Temperature ◽  
Superconducting State ◽  
Microstrip Antenna ◽  
High Temperature Superconductivity ◽  
High Temperature Superconductors ◽  
Experimental Studies ◽  
Analytical Form ◽  
Frequency Characteristics ◽  
Superconducting Film ◽  
Protective Device

The paper presents the results of experimental studies of a superconducting protective antenna, which consists of a high-temperature film deposited by a magnetron or a laser beam on a substrate. The work is carried out: - analysis of the selection criteria for the substrate type (Al2O3, Y2O3, SrTiO3, MgO) and the method for depositing a high-temperature superconducting film (HTSF) on its surface – YBaCuO - analysis of the methods of making contacts, which allow to reduce losses when passing a signal from the superconducting microstrip antenna to the waveguide path. The aim of this article is determination of the parameters of a prototype sample of a microstrip antenna device made from HTSF: transient characteristics of high-temperature superconductors, HTSF impulsive characteristics, recovery time of the superconducting state after the action of a powerful pulse on the protective device, the amplitude-frequency characteristics of the protective device in the superconducting state. This will allow to evaluate the possibility of using a microstrip antenna device made from high-temperature superconductors to protect the receiving systems from electromagnetic damage. The absence of a unified theory of high-temperature superconductivity leads to the need to select an analytical form of the functions of the amplitude-frequency characteristics of superconducting protection, and for this mathematical models are used in the programs "APPROX", "MathCAD14.0". The reliability of the obtained results of mathematical modeling of the processes of protection and recovery of the superconducting state after electromagnetic shock are confirmed in the course of experimental studies (an error of 0.15%).

A UNIQUE FINDING OF ZIRCON INTO BADDELEYITE TRANSFORMATION (THE ICHETJU ORE OCCURRENCE, THE MIDDLE TIMAN)

2018 ◽  
pp. 27-35
Author(s):  
S. G. Skublov ◽  
A. O. Krasotkina ◽  
A. B. Makeyev ◽  
O. L. Galankina ◽  
A. E. Melnik
Keyword(s):  
High Temperature ◽  
Experimental Studies ◽  
Middle Timan ◽  
Natural Analogues ◽  
Opposite Situation ◽  
Formation Conditions

Findings of the growth relationships between baddeleyite and zircon are rare, due to significant differences in the formation conditions of the minerals. A reaction replacement (partial to complete) of baddeleyite by zircon is possible during metamorphism accompanied by the interaction with high-Si fluids. The opposite situation, when zircon is replaced by baddeleyite, is extremely rare in the nature. Transformation of zircon from polymineral (compound) ore occurrence Ichetju (the Middle Timan) with the formation of microaggregates of baddeleyite, ratile and florencite has been found out. The size of the largest segregations of baddeleyite does not exceed 10 microns in diameter. Microaggregates are unevenly related to the rim of zircon with a thickness of 10 to 50 rfn, voids and cracks across the grain. Altered zircon rim (a mixture of newly formed minerals) is characterized by sharply increased composition of REE (especially LREE), Y, Nb, Ca, Ti. The composition of Th and U also increases. An overview of the experimental studies on the reaction between zircon and baddeleyite and single natural analogues allows to make a conclusion that the most likely mechanism of the transformation of zircon from ore occurrence Ichetju to baddeleyite (intergrowth with ratile and florencite) is due to the effect of interaction of primary zircon with high-temperature (higher than 500—600°C) alkaline fluids transporting HFSE (REE, Y, Nb, Ti). This is indirectly confirmed by the findings of zircon with anomalous high composition of Y and REE up to 100000 and 70000 ppm respectively.

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