㜞᷷વዉ䊋䊦䉪䈱⏛᳇ᶋ․ᕈ㩷
㩷
᧻ᧄᵗ
㧖ቯ⚐ᐔ
㧖㧖ኅේ
㧖㧖ࠕࠠ
㧖㧖ේ↰ ኡᴦ
㧖㧖㧖㩷
Magnetic Levitation Effect of High-Tc Superconducting Bulk
Hiroaki MATSUMOTO
㧖Junpei SADAKANE
㧖㧖Kazuya IEHARA
㧖㧖AKIRA
㧖㧖Kanji HARADA
㧖㧖㧖Since the discovery of high-temperature superconductivity, it has been studied for the applications and the developments in various fields. The superconducting fault-current limiter (FCL) is one of the superconducting applications, witch reduces the current to the level that the circuit breaker can easily work. The temperature becomes high caused by a Joule heat when fault electric current is restrained. We need high cooling efficiency to restore the accidental status to the normal one immediately.
We took note of cavities in the bulk and measured magnetic levitation effect as the basics. I fabricated the bulks that have many cavities by varying the sintering temperature and the pressure. As the result, I understood that cooling effect was increased and levitation time improved by lowering the cavity density.
Key words:
㩷Y123 superconductors, Magnetic Levitation Effect 㩷
㩷
㩷 䋱䋮䈲䈛䉄䈮㩷 㩷
㜞᷷વዉ߇⊒ߐࠇߡએ᧪㧘ࠃࠅ㜞⥃⇇᷷ᐲ 㧔6E㧕㧘ࠃࠅ㜞⥃⇇㔚ᵹኒᐲ㧔,E㧕ࠍ᳞ߡ㧘ᄙߊߩ
⎇ⓥ߇ߥߐࠇߡ߈ߚ
㧚߹ߚ㧘࡚ࠫࡈ࠰ࡦធวࠍ↪
ߚ 537+& ߣ߫ࠇࠆ㜞ᗵᐲߩ⏛᳇ࡦࠨߩ⎇ⓥ
߽⋓ࠎߦߥߐࠇߡࠆ
㧚
વዉߩᔕ↪ߩ৻ߟߦ㒢ᵹེ߇ࠆޕ㒢ᵹེߣߪ㔚 ജ♽⛔ߦ߅ߌࠆ⪭㔗╬ߦࠃࠆ⍴⛊㔚ᵹࠍ⍍ᤨߦᛥ
ߒߡޔㆤᢿࠍኈᤃߦߔࠆ㔚ജᯏེ ߩߎߣߢࠆޕㆊ 㔚ᵹ߇ᵹࠇߚߣ߈ߦવዉ⁁ᘒ߆ࠄᏱ㔚ዉ⁁ᘒߦォ⒖ ߔࠆߎߣࠍ↪ߒߡ↪ࠄࠇࠆޕߘߩߣ߈વዉߪ
㔚ᵹᛥᤨߦࠫࡘ࡞ᾲߦࠃࠅ㜞᷷ߣߥࠆ
ޕ
ᓟߩᓳᣥࠍㅦ߿߆ߦߔࠆߚߦ಄ළല₸ࠍ㜞ࠆᔅ ⷐ߇ࠆޕ
ߘߎߢᧄ⎇ⓥߢߪ Y123 ࡃ࡞ࠢߩኒᐲߦ⌕⋡ߒޔࡑ
ࠗࠬ࠽ലᨐߦࠃࠆ⏛⍹ᶋᤨ㑆ࠍ᷹ቯߒޔኒᐲߣ಄
ළലᨐߩ㑐ଥࠍ⺞ߴߚޕኒᐲߪᚑ᷷ᐲߣࡃ࡞ࠢᚑ
ᤨߩࡊࠬߦࠃߞߡᄌൻߐߖߚޕߘߩ⚿ᨐޔૐኒᐲ ൻߔࠆߎߣߦࠃࠅᶧ⓸⚛ߦࠃࠆ಄ළലᨐ߇㜞߹ࠅᶋ
ᤨ㑆߇ะߔࠆߎߣ߇ࠊ߆ߞߚޕ
䋲䋮ታ㛎ᣇᴺ㩷 㩷 㪉㪅㪈㩷 ⹜ᢱᣇᴺ㩷
⹜ᢱߩߦߪ㉄ൻࠗ࠶࠻࠙ࡓ (Y 2 O 3 ) ޔ㉄ࡃ
࠙ࡓ (BaCO 3 ) ޔ㉄ൻ㌃ (CuO) ࠍ↪ࠆޕߎࠇࠄߩ᧚ᢱࠍ
⚵ᚑᲧ߇ Y 㧦 Ba 㧦 Cu㧩1 㧦 2 㧦 3 ߣߥࠆࠃ߁ߦᷙวߔࠆޕ ߪߓ⦡߇⇣ߥࠆ㉄ൻࠗ࠶࠻࠙ࡓߣ㉄ൻ㌃ࠍ㋬ߦ
ࠇ⦡߇ဋ৻ߦߥࠆ߹ߢ⦟ߊᷙߗߚᓟޔ㉄ࡃ࠙ࡓ ࠍട߃ߐࠄߦᷙߗࠆޕߎࠇࠍ⚿ߐߖࠆߎߣߦࠃࠅ
વዉ‛⾰ߢࠆ㨅Ba 2 Cu 3 O 7 -x ࠍᓧࠆߎߣ߇ߢ߈ࠆޕ
ᰴߦਇ⚐‛ࠍขࠅ㒰߈⋡⊛ߩ⚵ᚑ‛ࠍᓧࠆߚߦ
ᚑࠍⴕߥ߁ޕᚑߦߪ㔚᳇Ἱࠍ↪ 10[ ͠ /min] ߢ 900 ͠߹ߢ᷷ޔ 5 ᤨ㑆ᜬߒߚᓟ 10[ ͠ /min] ߢቶ᷷߹
ߢ㒠᷷ߔࠆޕဋ৻ᕈࠍ㜞ࠆߚߦᚑࠍ 5 ࿁ⴕߞ ߚޕ
ߘߒߡᚑ᷷ᐲߣኒᐲᲧߩ㑐ଥࠍ⺞ߴࠆߚߦዊဳ
ߩ㊄ဳ ( ⋥ᓘ 1.3cm) ࠍ↪ߡࡃ࡞ࠢ⁁ߦᚑဳߔࠆޕࡊ
ࠬߪ 8kN ߣߒޔ 850͠ޔ 900͠ޔ 950͠ߢᧄᚑࠍⴕ ߞߚޕᧄᚑߢߪ⋡⊛᷷ᐲ߹ߢߪ 10[ ͠ /min] ߢ᷷ߒޔ 20 ᤨ㑆ᜬޔߘߒߡቶ᷷߹ߢ 1[ ͠ /min] ߢ㒠᷷ߒߚޕ
߹ߚࡊࠬߣኒᐲᲧߩ㑐ଥࠍ᳞ࠆߚᄢဳߩ㊄
ဳ(⋥ᓘ 6.0cm)ࠍ↪ߡᚑဳߒߚޕࡊࠬࠍ 25kNޔ
40kN ޔ 60kN ߣߒ 900 ͠ߢ⸥ߣหߓࡊࡠࠬߢᧄ
ᚑࠍⴕߞߚޕ
ේⓂฃઃ ᐔᚑ 20 ᐕ 9 1 ᣣ 㧖 ኾ⑼㔚ሶᖱႎࠪࠬ࠹ࡓᎿቇኾ
㧖㧖 㔚᳇㔚ሶᎿቇ⑼ 㧡ᐕ
㧖㧖㧖 㔚᳇㔚ሶᎿቇ⑼
㪉㪅㪉㩷 ⹜ᢱ䈱⹏ଔᣇᴺ㩷
ᧄ⎇ⓥߢߪવዉࡃ࡞ࠢౝߦࠆⓨሹߦ⌕⋡ߔࠆޕ ߘߩߚࡃ࡞ࠢߦߤߩߊࠄߩഀวߢⓨሹ߇ሽߔࠆ ߆ࠍߔߚߦኒᐲᲧࠍ↪ࠆޕߒߚ⹜ᢱߩኒᐲ Ყࠍᰴᑼߦࠃࠅ᳞ߚޕ
ߎߎߢࡃ࡞ࠢ⾰㊂ߣߪታ㓙ߩࡃ࡞ࠢߩ㊀㊂ߢࠅޔℂ
⺰⾰㊂ߣߪ Y123 ߩᩰሶቯᢙߣࡃ࡞ࠢߩⓍ߆ࠄ⸘▚
ߒߡ᳞ߚ୯ߢࠆޕߟ߹ࠅኒᐲᲧ߇ 100[%] ߩߣ߈ޔ
ⓨሹ߇ߥߊቢోߦኒߦ߹ߞߡࠆߎߣࠍᗧߒޔ
50[%] ߩߣ߈ߪࡃ࡞ࠢߩඨಽߪⓨሹߢࠆߎߣࠍᗧ
ߔࠆޕⓍߪࡁࠡࠬࠍ↪ߡࡃ࡞ࠢߩ⋥ᓘߣෘߐࠍ᷹
ቯߒޔ▚ߒߚޕ
ࡑࠗࠬ࠽ലᨐߦࠃࠆ⏛⍹ߩᶋ․ᕈࠍ Fig.1 ߦ␜
ߔޕ߹ߕࡃ࡞ࠢࠍᶧ⓸⚛ਛߢ಄ළߒޔࡀࠝࡑ࠶ࠢࠬ
⏛⍹ߩߦਸ਼ߖޔᶋᤨ㑆߅ࠃ߮ᶋ㜞ߐࠍ⸘᷹ߒߚޕ ᄢဳࡃ࡞ࠢߩ႐วߪޔࡃ࡞ࠢߩߦ⏛⍹ࠍਸ਼ߖ᷹ቯߒ ߚޕ৻ߟߩ⹜ᢱߦኻߒ 5 ࿁᷹ቯߒޔߘߩᐔဋࠍ᳞ߚޕ ᶧ⓸⚛ߦࠃࠆ಄ലᨐࠍ⏕߆ࠆߚߦࡃ࡞ࠢߦ
ᜬߐࠇࠆᶧ⓸⚛ߩ㊂ࠍ᷹ቯߒߚޕ߹ߕ಄ළ೨ߦࡃ
࡞ࠢߩ㊀㊂ࠍ᷹ࠆޕᰴߦࡃ࡞ࠢࠍᶧ⓸⚛ਛߦࠇ᳇
ᵃ߇ߥߊߥࠆ߹ߢචಽߦ಄ළߒߚᓟޔౣ߮ࡃ࡞ࠢߩ
㊀㊂ࠍ᷹ቯߒޔߘߩ㊀㊂ߩᏅࠍ᳞ߚޕ
߹ߚᩏဳ㔚ሶ㗼ᓸ㏜ 㧔 SEM 㧕ࠍ↪ߡ⹜ᢱ 㕙ߩ
ⷰኤࠍⴕߞߚޕ SEM ࠍ↪ߡࡃ࡞ࠢߩⓨሹߥߤࠍ⺞ߴ ߚޕ
㩷 㩷 㩷
䋳䋮ታ㛎⚿ᨐ䈫⠨ኤ㩷 㩷
㪊㪅㪈㩷 ᚑ᷷ᐲ䈫ᶋ․ᕈ㩷
ᧄᚑ᷷ᐲߣኒᐲᲧߩ㑐ଥࠍ Fig.2 ߦ␜ߔޕߎߩ࿑
ࠃࠅᚑ᷷ᐲ߇㜞߶ߤኒᐲᲧ߽㜞ߊߥߞߡࠆߎߣ ߇ಽ߆ࠆޕߎࠇߪ㜞᷷ߢ⚿ߔࠆߣޔ⚿᥏☸߇ࠃࠅ
❗ߔࠆߚߛߣᕁࠊࠇࠆޕ
ኒᐲᲧߣᶋᤨ㑆ߩ㑐ଥࠍ Fig.3 ߦ␜ߔޕኒᐲᲧߩૐ ਅߦޔᶋᤨ㑆߇ะߔࠆะߦࠆߎߣ߇ࠊ߆ ࠆޕኒᐲᲧ߇ૐߣ߁ߎߣߪࡃ࡞ࠢߦᄙᢙߩⓨሹ߇
ࠆߣ⠨߃ࠄࠇࠆޕߎߩⓨሹౝߦᶧ⓸⚛߇ࠅㄟߺ
಄ലᨐ߇㜞߹ߞߚߚߢߪߥ߆ߣ⠨߃ࠄࠇࠆޕ ኒᐲᲧߣᶋ㜞ߐߩ㑐ଥࠍ Fig.4 ߦ␜ߔޕૐኒᐲൻߔ ࠆߎߣߦࠃࠅᶋᤨ㑆߇ะߒߚ৻ᣇޔᶋ㜞ߐߪૐ ߊߥࠆ⚿ᨐߣߥߞߚޕ
㨇㧑㨉 ℂ⺰⾰㊂
ࡃ࡞ࠢ⾰㊂
ኒᐲᲧ = × 100
㪍㪇 㪍㪌 㪎㪇 㪎㪌 㪏㪇
㪏㪇㪇 㪏㪌㪇 㪐㪇㪇 㪐㪌㪇 㪈㪇㪇㪇
㪪㫀㫅㫋㪼㫉㫀㫅㪾㩷㪫㪼㫄㫇㪼㫉㪸㫋㫌㫉㪼㪲㷄㪴
㪛㪼㫅㫊㫀㫋㫐㩷㫉㪸㫋㫀㫆㪲㩼㪴
Fig.2 The relation of sintering temperature and density ratio
㪇 㪈㪇 㪉㪇 㪊㪇 㪋㪇
㪍㪇 㪍㪌 㪎㪇 㪎㪌 㪏㪇
㪛㪼㫅㫊㫀㫋㫐㩷㫉㪸㫋㫀㫆㪲㩼㪴
㪣㪼㫍㫀㫋㪸㫋㫀㫆㫅㩷㫋㫀㫄㪼㪲㫊㪴
㪇 㪈 㪉 㪊 㪋 㪌
㪍㪇 㪍㪌 㪎㪇 㪎㪌 㪏㪇
㪛㪼㫅㫊㫀㫋㫐㩷㫉㪸㫋㫀㫆㪲䋦㪴
㪣㪼㫍㫀㫋㪸㫋㫀㫆㫅㩷㪿㪼㫀㪾㪿㫋㪲㫄㫄㪴
Fig.1 Magnetic levitation by Meissner effect Superconducting
Bulk
Magnet
Fig.3 The relation of density ratio and levitation time
Fig.4 The relation of density ratio
and levitation height
㪊㪅㪉㩷 䊒䊧䉴䈫ᶋ․ᕈ㩷
ᄢဳࡃ࡞ࠢࠍ↪ߡ᷹ቯߒߚࡊࠬߣኒᐲᲧߩ㑐
ଥࠍ Fig.5 ߦ␜ߔޕߎߩ࿑߆ࠄࡊࠬࠍૐߊߔࠆߎ
ߣߦࠃߞߡኒᐲᲧ߇ਅ߇ࠆߎߣ߇ࠊ߆ߞߚޕߎࠇߦࠃ ࠅࡊࠬߢߩᚑဳᤨߩኒᐲ߇ᧄᚑᓟߦ߽ᓇ㗀ߔࠆߎ ߣ߇ಽ߆ߞߚޕ
ᄢဳࡃ࡞ࠢࠍ↪ߡ᷹ቯߒߚኒᐲᲧߣᶋᤨ㑆ߩ㑐
ଥࠍ Fig.6 ߦ␜ߔޕࡊࠬߦࠃࠆኒᐲᲧߩᄌൻߢ߽
ᚑ᷷ᐲᄌൻᤨߣห᭽ߦૐኒᐲൻߔࠆߎߣߦࠃࠅᶋ
ᤨ㑆߇ะߔࠆߎߣ߇ಽ߆ߞߚޕ
ኒᐲᲧߣࡃ࡞ࠢౝߦᜬߐࠇࠆᶧ⓸⚛㊂ߩ㑐ଥࠍ
Fig.7 ߦ␜ߔޕ Fig.7 ࠃࠅࡃ࡞ࠢౝߦᶧ⓸⚛߇ࠅㄟ
ࠎߢࠆߎߣ߇⏕ߢ߈ߚޕߎࠇߪኒᐲᲧߩૐਅߦ
ޔනⓍߚࠅߩᶧ⓸⚛ᜬ㊂߇Ⴧടߒߡࠆ ߎߣࠍ␜ߒߡࠆޕ
㪊㪅㪊㩷 䌓䌅䌍䈮䉋䉎㕙ⷰኤ㩷
ᄢဳࡃ࡞ࠢߩ⹜ᢱ SEM ౮⌀ࠍ Fig.8 ߦ␜ߔޕSEM ౮⌀߆ࠄታ㓙ߦࡃ࡞ࠢౝߩⓨሹߩ᭽ሶࠍࠆߎߣ߇ߢ ߈ࠆޕ⚂㧡Ǵ m ߩવዉߩ☸ሶ߇⚿ߔࠆߎߣߦࠃࠅ
⚿วߒߡࡃ࡞ࠢࠍᒻᚑߒߡࠆޕߘߩ☸ሶߣ☸ሶߩ㑆 ߦⓨሹ߇ሽߒߡࠆޕߎࠇࠄߩⓨሹߪࡊࠬ߇ૐ
ߣ߈ߦߪᄢ߈ߊᄙᢙሽߒߡࠆޕߎࠇߪࡊࠬ
߇ૐߣ߈ኒᐲᲧ߽ૐߊߥߞߚ⚿ᨐࠍⵣઃߌߡࠆޕ
㩷 䋴䋮 ⠨ ኤ㩷
㪌㪌 㪍㪇 㪍㪌 㪎㪇 㪎㪌
㪇 㪉㪇 㪋㪇 㪍㪇 㪏㪇
㪧㫉㪼㫊㫊㫌㫉㪼㪲㫂㪥㪴
㪛㪼㫅㫊㫀㫋㫐㩷㫉㪸㫋㫀㫆㪲䋦㪴
㪇 㪇㪅㪈 㪇㪅㪉 㪇㪅㪊 㪇㪅㪋 㪇㪅㪌 㪇㪅㪍
㪌㪌 㪍㪇 㪍㪌 㪎㪇 㪎㪌
㪛㪼㫅㫊㫀㫋㫐㩷㫉㪸㫋㫀㫆㪲㩼㪴 㪨㫌㪸㫅㫋㫀㫋㫐㩷㫆㪽 㩷㩷㩷㩷㩷㩷㩷㩷㩷㫃㫀㫈㫌㫀㪻㩷㪥㪉㩷㪲㪾㪆㪺㫄㪊㪴
㪇 㪉㪇 㪋㪇 㪍㪇 㪏㪇 㪈㪇㪇 㪈㪉㪇
㪌㪌 㪍㪇 㪍㪌 㪎㪇 㪎㪌
㪛㪼㫅㫊㫀㫋㫐㩷㫉㪸㫋㫀㫆㪲䋦㪴
㪣㪼㫍㫀㫋㪸㫋㫀㫆㫅㩷㫋㫀㫄㪼㪲㫊㪴
(c) Pressure 60[kN]
Fig.5 The relation of pressure and density ratio
Fig.6 The relation of density ratio and levitation time
Fig.7 The relation of density ratio and quantity of liquid N
2Fig.8 SEM images of bulks (b) Pressure 40[kN]
(a) Pressure 25[kN]
ࡃ࡞ࠢᤨߩᧄᚑ᷷ᐲࠆߪࡊࠬࠍᄌൻ ߐߖࠆߎߣߦࠃࠅޔኒᐲࠍᄌൻߐߖࠆߎߣ߇ߢ߈ࠆޕ ߘߒߡኒᐲࠍૐߊߔࠆߎߣߦࠃࠅࡃ࡞ࠢౝߦⓨሹ߇ߢ ߈ߘߎߦᶧ⓸⚛߇ᜬߐࠇᶋᤨ㑆߇ะߒߚޕߎ ࠇߪⓨሹౝߦᶧ⓸⚛߇ࠆߎߣߦࠃࠅ಄ലᨐ߇㜞
߹ߞߚߚߛߣᕁࠊࠇࠆޕ
ᶧ⓸⚛ਛߢ 77[K] ߦ಄ළߐࠇߚࡃ࡞ࠢߪ⥃⇇᷷ᐲ
ߢࠆ⚂ 90[K]ߦߥࠆ߹ߢᶋߒ⛯ߌࠆߣ⠨߃ࠄࠇࠆޕ
㨅 123 ߩਥᚑಽߢࠆ㌃ߣᶧ⓸⚛ߩනⓍߚࠅ ߩᲧᾲࠍߊࠄߴࠆߣ㌃㧦 3.392 [J/cm
3㨯 K] ޔᶧ⓸⚛㧦 0.839[J/cm
3㨯 K] ߢࠆޕવዉ߆ࠄᏱવዉߦォ⒖ߔࠆ
߹ߢߦ 13[K]ߩ᷷ᐲࠍᔅⷐߣߔࠆߩߢޔߘࠇߙࠇ
ᔅⷐߥᾲ㊂ߪ㌃㧦 44.1[J/cm
3] ޔᶧ⓸⚛㧦 10.9[J/cm
3] ߣ㌃ߩ߶߁߇ᄢ߈ޕߒ߆ߒᶧ⓸⚛ߦߪ᳇ൻᾲ߇
ࠅනⓍߚࠅ 160.6[J/cm
3] ߢࠆޕߘߩߚว⸘
ߔࠆߣ㌃㧦44.1 [J/cm
3]ߦኻߒᶧ⓸⚛㧦 171.5 [J/cm
3] ߣߥࠅᶧ⓸⚛ࠍࡃ࡞ࠢౝߦ ߔࠆߎߣߦࠃࠅ಄
ലᨐ߇㜞߹ࠆޕ
ኒᐲᲧߩૐਅߦᶋ㜞ߐ߇ૐਅߒߚޕߘ߽ߘ߽
ࡑࠗࠬ࠽ലᨐߣߪવዉౝ ㇱ߳ߩᄖㇱ⏛႐ߩଚ
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