Surface resistance of large-area Tl2Ba2CaCu2O8 thin films at microwave and millimeter wave frequencies measured by three noncavity techniques

Holstein, W.L.; Parisi, L. A.; Shen, Zhiyuan; Wilker, C.; Brenner, Michael; Martens, J.

doi:10.1007/bf00625746

Cited by 44 publications

(19 citation statements)

References 40 publications

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“…Values for T c up to 127 K have been reported for small quantities of specially processed powders. 13,14 This phase can be formed with a surface roughness and defect level low enough to allow for patterning of long, narrow lines which maintain good electrical properties. on the practical use of the Tl 2 Ba 2 Ca 2 Cu 3 O 10 phase, in spite of its higher T c .…”

Section: Introductionmentioning

confidence: 99%

Process optimization for the fabrication of Tl₂Ba₂Ca₂Cu₃O₁₀ thin films

Holstein

Parisi

1996

J. Mater. Res.

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A process has been developed for the fabrication of nearly single phase superconducting Tl2Ba2Ca2Cu3O10 thin films on (100) LaAlO3 substrates with a superconducting transition temperature Tc of 120 K and low microwave surface resistance at temperatures up to 110 K. Amorphous BaCaCuO precursor films were first deposited by rf magnetron sputtering and then thallinated at elevated temperatures. The double TlO layer phases (Tl2Ba2Ca2Cu3O10 + Tl2Ba2CaCu2O8) formed preferentially over the single TlO layer phases (TlBa2Ca2Cu3O9 + TlBa2CaCu2O7) at high Tl2O partial pressures. Thin films containing Tl2Ba2Ca2Cu3O10 and a small amount of CuO were prepared from Cu-rich precursor films (Cu/Ba > 1.7), while lower Cu content led to the formation of Tl2Ba2CaCu2O8 as a secondary phase. Tl2Ba2Ca2Cu3O10 film epitaxy was enhanced by carrying out the thallination in reduced oxygen partial pressures of 0.01–0.05 atm. Following the thallination step, the Tl2Ba2Ca2Cu3O10 thin films had a superconducting transition temperature Tc of only 106 ± 4 K. An additional 62 h anneal at 800 °C or an 8 h anneal at 850 °C in a Tl2O/O2 atmosphere increased the Tc to 120 K. The increase in Tc was accompanied by a decrease in the c-axis lattice constant, an enhancement in the long-range order in the c-direction, and the formation of a small amount of Tl2Ba2CaCu2O8 as a secondary phase. Minimization of surface resistance at high temperature (95–110 K) requires that the fraction of Tl2Ba2CaCu2O8 secondary phase in the films be kept low. Process routes are also described for the formation of nearly single phase TlBa2Ca2Cu3O9 and TlBa2CaCu2O7 thin films and the formation of a new ordered intergrowth phase, Tl4Ba4Ca3Cu5O18, which consists of alternating Tl2Ba2CaCu2O8 and Tl2Ba2Ca2Cu3O10 layers.

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Section: Introductionmentioning

confidence: 99%

Process optimization for the fabrication of Tl₂Ba₂Ca₂Cu₃O₁₀ thin films

Holstein

Parisi

1996

J. Mater. Res.

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“…Two-sided 0.65 pm thick Tl,Ba,CaCu,O, HTS thin films deposited on 2-inch diameter 20-mil LaA103 wafers were used to fabricate the HTS filters. [9] The power handling of Tl,Ba,CaCu,O, HTS has been reported elsewhere.…”

Section: Hts Filter Design and Fabricationmentioning

confidence: 99%

Full 2-Port Calibrated S-Parameter Measurements up to 30 W of High-Temperature Superconducting Filters

Wilker

Shen

Pang

et al. 1996

47th ARFTG Conference Digest

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We have configured, tested and qualified a high-power network analyzer that can deliver between 100 pW and 30 W to a DUT. This system can be readily switched between low-power and high-power levels, output power leveled and fully calibrated over its full power range. This calibrated instrument was used to measure the performance of high-power high-temperature superconducting (HTS) filters. The performance of these prototype filters measured at an operating power of 8 W was:c0.02 dB in-band insertion loss, 0.2 dB in-band ripple, >17 dB in-band retum loss and >SO dB off-band rejection..

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“…Nevertheless, there are a few European activities on the in-situ growth of epitaxial BSCCO films13'14 and the ex-situ growth of TBCCO films with a final Tl-diffusion process leading to granularity.1547 BSCCO films still show extremely high R values, which are most probably due to phase impurities or weak links as concluded from measurements on single tal18 The TBCCO films suffer mainly from granularity especially at high field levels and cannot compete so far with the best results obtained by 19 No microwave results have been reported so far on the infinite layer or Hg FITS compounds. In Europe, YBCO is therefore still the FITS of choice for microwave applications.…”

Section: Choice Of Hts Substrates and Deposition Techniquesmentioning

confidence: 99%

<title>High-temperature superconductor microwave applications in Europe</title>

1994

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European activities on the optimization of microwave properties and applications of HTS for microwave components and subsystems are reviewed. For that purpose, the various contributions are discussed in terms of relevant material issues and are related to different classes of applications. Passive as well as active microwave devices based on both linear and nonlinear conductivity properties of I-ITS between 0.5 and 500 GHz are covered. Additionally, some application categories are discussed from a general point of view. It will be shown that the present state of technology has made possible the successful demonstration of many single HIS components and of first super-semiconducting hybrid subsystems. INTRODUCTIONSince the discovery of high-temperature superconductors (HTS), enormous technological improvements in the deposition and physical charactenzation of high-quality thin HTS films and Josephson junctions have been reported. In parallel to this development, considerable progress has been achieved in the design, fabrication and functional demonstration of single microwave components as well as of integrated subsystems which significantly benefit from utilizing I-ITS. This progress can be regarded as the result of various complementary activities of many groups from all over the world.This review intends to relate the various contributions, reported so far from European groups, to different classes of applications which are partially discussed from a more general point of view. Such a classification allows furthermore to compare and to identify interrelations between corresponding publications. There are some particular reasons for concentrating the discussion on European activities: 1 . Many reports were presented at European conferences and workshops which were scarcely attended by scientists from overseas. This paper may therefore help to cope with the "information gap". 2. European funding policy drives groups from different places to arrange their activities with optimum convergence. This paper may therefore help to give a "conclusive survey" on microwave applications of HTS in Europe.The following analysis is based on a selection of representative and most recent European contributions, and it should not be complete in every regard. In some cases the results are related to technologically advanced work elsewhere. With respect to the potential of short-term applications of HIS, research and development at frequencies between 0.5and500 GHz is mainly considered. Although work on digital electronics will not be covered, the authors are well aware of its importance for future integrated operational HTS systems. In Sec. 2, material issues relevant for microwave applications of HTS are summarized.Sections 3 and 4 review microwave components based on linear and nonlinear conductivity properties of FITS, respectively. Sec. 5 concludes the paper by evaluating the results on single devices with respect to integrated HTS microwave systems. MATERIAL ISSUES Basic microwave properties of superconductorsThe interaction b...

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Surface resistance of large-area Tl2Ba2CaCu2O8 thin films at microwave and millimeter wave frequencies measured by three noncavity techniques

Cited by 44 publications

References 40 publications

Process optimization for the fabrication of Tl₂Ba₂Ca₂Cu₃O₁₀ thin films

Process optimization for the fabrication of Tl₂Ba₂Ca₂Cu₃O₁₀ thin films

Full 2-Port Calibrated S-Parameter Measurements up to 30 W of High-Temperature Superconducting Filters

<title>High-temperature superconductor microwave applications in Europe</title>

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Surface resistance of large-area Tl2Ba2CaCu2O8 thin films at microwave and millimeter wave frequencies measured by three noncavity techniques

Cited by 44 publications

References 40 publications

Process optimization for the fabrication of Tl2Ba2Ca2Cu3O10 thin films

Process optimization for the fabrication of Tl2Ba2Ca2Cu3O10 thin films

Full 2-Port Calibrated S-Parameter Measurements up to 30 W of High-Temperature Superconducting Filters

<title>High-temperature superconductor microwave applications in Europe</title>

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Process optimization for the fabrication of Tl₂Ba₂Ca₂Cu₃O₁₀ thin films

Process optimization for the fabrication of Tl₂Ba₂Ca₂Cu₃O₁₀ thin films