Oxide Heterostructure

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Oxide Heterostructure

• Shuhua Liang
• UTK Physics Dept.

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Perovskite Stucture ABO3
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LCMO (magnetic material)La0.67Ca0.33MnO3
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High Tc Superconductor Lattice

• LSCO (High Tc Sc)
• (La1-xSrxCuO3 )

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YBCO High Tc Sc

• YBa2Cu3O7-x
• CuO2 Plane
• More layers Higher Tc
• Distance
• Carriers in CuO2 Plane

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Metallic Interfaces between Insulators

• LaTiO3 layers (bright) of varying thickness
  spaced by 5 layers of SrTiO3

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• LaTiO3
• La 3 one more e
• Ti 3
• Mott insulator
• A0.397nm

• SrTiO3
• Sr 2
• Ti 4
• Band insulator
• A0.391nm

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Charge leakage

• the Ti3 signal is considerably wider than that
  of the La
• Ti3extra electron
• The tail of Ti3 have a decay length of 1nm as
  an order of screening length!

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Metallic Structure

• Fraction of Ti3 is a function of the number of
  LaTiO3 unit cells.
• Conductivity is a function of the thickness of
  LaTi3 and SrTi3

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CMR

• Colossal magnetoresistance

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LaMnO3
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Double-exchange mechanism

• Ca 2 cause electron free to move.

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Oxide heterostructure interface
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Ferromagnetic/Sc oxide interface

• Sc YBa2Cu3O7-x

• FM La0.67Ca0.33MnO3

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interface
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Electrons transfer
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Thank you!