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Growth of Superconducting Bi2Sr2CaCu2O8+δ(Bi-2212) Single Crystal Whiskers and the Characteristics

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Abstract
The single-crystal whiskers of Bi2Sr2CaCu2O8+δ(Bi-2212) have attracted much attention because they have perfect crystallinity, are free of dislocations, show peculiar dimensions with extremely small cross-sections, and have excellent superconducting properties. The developments suggest that whiskers might be used in the fabrication of new electronic devices using intrinsic Josephson junctions and related phenomena, such as Josephson plasma oscillations. Stacked junctions have been fabricated by using Bi-2212 whiskers and are thought to be prospective candidates for high-frequency applications of the intrinsic Josephson effect.
All studies on Bi-2212 whisker growth so far have been based on flux flow method. The whiskers are grown by annealing only melt-quenched glassy precursors that dope Al. We have successfully grown Bi-2212 whiskers directly from the sintered pellets of polycrystalline precursor including Te that had not passed through a melt-quenched glassy state. These whiskers have excellent crystallinity with a small amount of Bi-2223 intergrowth and a very uniform multibranched structure of the current (I) -voltage (V ) characteristics due to the intrinsic Josephson junctions along the c-axis, suggesting that the whiskers are homogeneous and of good quality.
We have succeeded in the growth of superconducting Bi-2212 single crystal whiskers with a Te-doped method. We use a Te-doped precursor with the mixed pure powders Bi2O3, SrCO3, CuO and TeO2 into the ratios of Bi2Sr2Ca2Cu2.5Te0.5Ox. Bi-2212 single crystal whiskers have grown through the pellet surface 2-4 mm in length and 20-100 ?m in width. Characteristics of whiskers were investigated by the resistance-temperature (R-T ), X-ray diffraction (XRD) and current-voltage (I-V ) measurements. The R-T characteristics in ab-plane of the whiskers showed that their Tc,on and Tc,end were about 106 K and 75 K, respectively and confirmed that the whiskers had Bi-2212 single crystal phase by XRD pattern. The I-V curves showed multi-branch structures of intrinsic Josephson junctions (IJJs) as evidence of c-axis transport characteristics.
Author(s)
오상율
Issued Date
2011
Awarded Date
2011. 8
Type
Dissertation
URI
http://dcoll.jejunu.ac.kr/jsp/common/DcLoOrgPer.jsp?sItemId=000000005548
Alternative Author(s)
Oh, Sang-Yul
Affiliation
제주대학교
Department
대학원 메카트로닉스공학과
Advisor
김상재
Table Of Contents
1. Introduction 2
1.1 Introduction 2
1.2 Josephson Junction 3
1.3 Intrinsic Josephson junctions4
1.4 Applications5
1.4.1 Single Electron Transistor(SET) 5
1.4.2 Terahertz Application 5
1.5 Summary 9
2. Growth of Bi-2212 single crystal whiskers 11
2.1 Introduction 11
2.2 The growth process 12
2.3 Results and discussion 12
2.4 Summary 19
3. Three-Dimensional Focused Ion Beam Milling Technique 20
3.1 Introduction 20
3.2 The Focused Ion Beam 20
3.2.1 Fundamental Operating Principle of FIB 22
3.3 Fabrication of Josephson junctions 22
3.4 Summary 24
4. Intrinsic Josephson junctions Stack of Bi-2212 25
4.1 Introduction 25
4.2 Experimental details 27
4.3 Results and discussion 32
4.4 Summary 33
5. Conclusions 34
Degree
Master
Publisher
제주대학교 대학원
Citation
오상율. (2011). Growth of Superconducting Bi2Sr2CaCu2O8+δ(Bi-2212) Single Crystal Whiskers and the Characteristics
Appears in Collections:
Faculty of Applied Energy System > Mechatronics Engineering
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