Mass transport of Y(dpm)2 Ba(dpm)5· OH· 2Ho and Cu (dpm)2 by a carrier gas(argon) was theoretically considered and experimentally studied as a function of the system with operating parameters including tempe...Mass transport of Y(dpm)2 Ba(dpm)5· OH· 2Ho and Cu (dpm)2 by a carrier gas(argon) was theoretically considered and experimentally studied as a function of the system with operating parameters including temperature, carrier gas flow rate and system pressure. The experimental results are in a good agreement with the theoretical prediction. The mechanism of mass transport of these organometallic precursors and their use for YBCO film stoichiometry control and reproducibility are discussed.展开更多
Excellent epitaxial growth of supercon-ducting YBaCuOthin films have beenrealized on(100)SrTiOand(100)ZrOsubstrates by a planar rf or DC-magnetronsputtering apparatus with UHV system.Thequality of growth and the epita...Excellent epitaxial growth of supercon-ducting YBaCuOthin films have beenrealized on(100)SrTiOand(100)ZrOsubstrates by a planar rf or DC-magnetronsputtering apparatus with UHV system.Thequality of growth and the epitaxial orientationof the film strongly depended on substratetemperature,the substrate orientation and ox-ygen partial pressure.The films exhibitedsuperconducting onset at 92K and zero resist-ance at 90K with critical current density of展开更多
By the r. f. magnetron sputtering method, the CeO_2 buffer layers were prepared on (100) LaAlO_3 sub-strates. The results of X-ray diffraction and Ф-scan indicated that the CeO_2 films were unique ( 100)-orientedand ...By the r. f. magnetron sputtering method, the CeO_2 buffer layers were prepared on (100) LaAlO_3 sub-strates. The results of X-ray diffraction and Ф-scan indicated that the CeO_2 films were unique ( 100)-orientedand epitaxial. The YBa_2Cu_3O_(7-6)(YBCO) films, which were deposited on the CeO_2/LaAlO_3 by d. c. magnetronsputtering, exhibited transition temperatures of 89～91 K,and had critical current densities exceeding 10￣6 A/cm￣2 at 77 K in zero magnetic field.展开更多
The X-ray Ф-scan technique was applied to determine the in-plane orientation relationship of the high T_csuperconductins bi-epitaxial junction. The result shows that the in-plane orientation relation of the films in ...The X-ray Ф-scan technique was applied to determine the in-plane orientation relationship of the high T_csuperconductins bi-epitaxial junction. The result shows that the in-plane orientation relation of the films in thetwo sides of the grain boundary can be easily obtained with this method. By controlling the growth condition,a 45° YBCO grain boundary can be made on the SrTiO_3 substrate.展开更多
Before 1986, people were hesitant to believe that superconductors could operate at such high temperatures, well above the readily liquid nitrogen regime. It was a dream! Shortly after the discovery of
I. INTRODUCTION Since the discovery of superconductivity above 40 K in the La-Ba-Cu-O system andabove 90 K in Y-Ba-Cu-O oxides, tremendous effort has been made to study the properties of high-T_c superconducting thin ...I. INTRODUCTION Since the discovery of superconductivity above 40 K in the La-Ba-Cu-O system andabove 90 K in Y-Ba-Cu-O oxides, tremendous effort has been made to study the properties of high-T_c superconducting thin films. For the preparation of superconducting films two main techniques, the e-beam evaporation and sputtering, have been used. The processes展开更多
No sooner had the high T_c superconducting oxides been discovered than the wide interest was exhibited in the research of the electronic structure and ionic valence state of these kinds of materials. Based on theoreti...No sooner had the high T_c superconducting oxides been discovered than the wide interest was exhibited in the research of the electronic structure and ionic valence state of these kinds of materials. Based on theoretic calculations and experimental results of the X-ray photoelectron spectroscopy (XPS)and the electron-energy-loss spectroscopy (EELS), it展开更多
INTRODUCTIONIn order to improve the efficiency of the electrically small antenna, which has the physical extension smaller than the maximum free space wavelength transmitted or received, superconducting materials bega...INTRODUCTIONIn order to improve the efficiency of the electrically small antenna, which has the physical extension smaller than the maximum free space wavelength transmitted or received, superconducting materials began to be utilized in fabricating antennas since 1960s. In 1988, the Birmingham group of UK made for the first time the small dipole antennas展开更多
文摘Mass transport of Y(dpm)2 Ba(dpm)5· OH· 2Ho and Cu (dpm)2 by a carrier gas(argon) was theoretically considered and experimentally studied as a function of the system with operating parameters including temperature, carrier gas flow rate and system pressure. The experimental results are in a good agreement with the theoretical prediction. The mechanism of mass transport of these organometallic precursors and their use for YBCO film stoichiometry control and reproducibility are discussed.
文摘Excellent epitaxial growth of supercon-ducting YBaCuOthin films have beenrealized on(100)SrTiOand(100)ZrOsubstrates by a planar rf or DC-magnetronsputtering apparatus with UHV system.Thequality of growth and the epitaxial orientationof the film strongly depended on substratetemperature,the substrate orientation and ox-ygen partial pressure.The films exhibitedsuperconducting onset at 92K and zero resist-ance at 90K with critical current density of
文摘By the r. f. magnetron sputtering method, the CeO_2 buffer layers were prepared on (100) LaAlO_3 sub-strates. The results of X-ray diffraction and Ф-scan indicated that the CeO_2 films were unique ( 100)-orientedand epitaxial. The YBa_2Cu_3O_(7-6)(YBCO) films, which were deposited on the CeO_2/LaAlO_3 by d. c. magnetronsputtering, exhibited transition temperatures of 89～91 K,and had critical current densities exceeding 10￣6 A/cm￣2 at 77 K in zero magnetic field.
文摘The X-ray Ф-scan technique was applied to determine the in-plane orientation relationship of the high T_csuperconductins bi-epitaxial junction. The result shows that the in-plane orientation relation of the films in thetwo sides of the grain boundary can be easily obtained with this method. By controlling the growth condition,a 45° YBCO grain boundary can be made on the SrTiO_3 substrate.
文摘Before 1986, people were hesitant to believe that superconductors could operate at such high temperatures, well above the readily liquid nitrogen regime. It was a dream! Shortly after the discovery of
基金Project supported by the National Center for Research and Development on Superconductivity and the Sci ence Foundation of Academia Sinica
文摘I. INTRODUCTION Since the discovery of superconductivity above 40 K in the La-Ba-Cu-O system andabove 90 K in Y-Ba-Cu-O oxides, tremendous effort has been made to study the properties of high-T_c superconducting thin films. For the preparation of superconducting films two main techniques, the e-beam evaporation and sputtering, have been used. The processes
基金Project supported by the National Center for Research and Development on Superconductivity.
文摘No sooner had the high T_c superconducting oxides been discovered than the wide interest was exhibited in the research of the electronic structure and ionic valence state of these kinds of materials. Based on theoretic calculations and experimental results of the X-ray photoelectron spectroscopy (XPS)and the electron-energy-loss spectroscopy (EELS), it
文摘INTRODUCTIONIn order to improve the efficiency of the electrically small antenna, which has the physical extension smaller than the maximum free space wavelength transmitted or received, superconducting materials began to be utilized in fabricating antennas since 1960s. In 1988, the Birmingham group of UK made for the first time the small dipole antennas
