Proj.1 Electric conductivity in metals , semiconductors and superconductors

1
Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

• Introduction
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• ??? Band gap ??
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2
Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• ???(conduction Band)?? ? ????(quasi-free
  electron)
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vD drift velocity (??? ?? ?? ? ??? ????)
mobility
3
Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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4
Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• Excitation of electrons from valance band to
  conduction band

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5
Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• 1911? H.K.???? ??? ???? ??
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  K?? ????? ??? ??? ??? ??
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6
Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• ???? Tc
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• ??????? ?? ???? ????? Hc ??? ???? ?? ?? ??? ??? ?
  

7
Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• 1933? Meissner? Oschenfeld? ??

8
Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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TC ???? ?? ??? ??? ??? ?
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TC ???? ???? ??? ?? ????? ???
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Type I ?? ?? ????
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9
Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• Ceramic ??/Type II
• Georg Bednorz and Alex Muller ??
• 1886 ?? 30 K? ????? ?? lanthanum-barium-copper
  oxide ceramic in 1986 with Tc of 30 K.
• ?? ????(???? 77 K)

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Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• BCS THEORY
• 1975? John Bardeen, Leon Cooper, and Robert
  Schrieffer? ??? ??? ????
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• Copper pair? Boson?. ?? ??? ??? ??? ? ??

e
Band gap
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• Band gap ?? ?? ? ??? ???? ???? ??? ???? ??
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11
Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• ??(Novle metal, semiconductor)

586 80/82

• Temperature range - 80 C to 400
• Resistance at 20 C 100 Ohm approx.
• Resistance change within the specified
  temperature range 1 3.5

Novle metal (586 80)

• Temperature range - 80 C to 200
• Resistance at 20 C 200 Ohm approx.
• Resistance change within the specified
  temperature range 1 10000

Semiconductor (586 82)
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Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• ?? ???? Electric oven(555 81)Safety connection
  box(502 061)

• Electrically heated, ceramic oven with
  cylindrical heating chamber and hole for
  temperature measurement.
• Temperature max. 600 C

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Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• ????(666 193) ????(524 045)
• NiCr-Ni thermocouple.
• Measurement range - 200 to 1100 C

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Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• Current supply box(524 031)
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15
Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• Sensor CASSAY(524 010) CASSAY lab software(524
  200)
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Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

• ??
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• ?????? (667 552)
• ?? YBa2Cu3O7-x
• 4-point measurement
• Current source (250 mA)
• ?? ??(UR)
• ????(UT )Iridium resistor
• ?? YBa2Cu3O7-x
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• ???? thermistor

667 552
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Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• ?????? Sensor CASSAY CASSAY lab software
• ?? T ? ? ?? UR ??? ?? ??

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Proj.1 Electric conductivity in metals ,
semiconductors and superconductors

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• Curve fitting with
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• Curve fitting with
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0oC ??? ??