Prof. Kee-Joe Lim

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• Prof. Kee-Joe Lim
• kjlim_at_chungbuk.ac.kr, 261-2424
• School of Electrical and Computer Engineering
• Chungbuk National University
• http//imt.cbucc.net
• 2007/9/1

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Superconductivity technologyFundamentals(Zero
resistance)(Meissner effect)
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Summary on superconductivity
- Perfect conduction -----gt Zero electrical
resistance - Perfect diamagnetism ----gt Meissner
effect - 3-D envelopes for critical temperature,
magnetic field, current density - Type I and Type
II superconductors - AC loss - HTS - Popular
superconductors NbTi, Nb3Sn, Nb3Al, Nb, YBCO,
BSCCO, TBCCO, ...
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Perfect conductor (Electrical resistivity of
superconductor Less than 10-20 ohm.cm)
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Meissner effect (perfect diamagnetism) --gt
figure Discovered by Meissner and Ochsenfeld in
1934, the Meissner effect describes the absence
of magnetic field within the bulk of a
superconductor (perfect diamagnetism). Experiment
al validation of Meissner effect.
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Magnetic levitation using superconductivity
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lt????gt
??????? B0 ??. ??? ????? ?? ?
Zero resistance? B0? ??? ???.
????? ??????(perfect diamagnetic materials) ??.
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Brief history of superconductivity 1908 Helium
liquefied by Kammerlingh Onnes1911 Superconductiv
ity of Hg is discovered. ? R 0.1913 Superconduc
ting magnet concept1916 Failed attempt to make
superconducting magnet1934 Meissner effect ? B
0.1930 Thermodynamics of Type I
superconductor1935 Penetration depth, ? Type II
superconductor (PbBi) by deHaas Voogd1950