Title page for etd-0731115-111753


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URN etd-0731115-111753
Author Tzu-chieh Huang
Author's Email Address No Public.
Statistics This thesis had been viewed 5568 times. Download 7 times.
Department Physics
Year 2014
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Study of Magnetic and Transport Properties of La0.7Sr0.3MnO3 (111)Thin Films
Date of Defense 2015-07-25
Page Count 54
Keyword
  • Magnetic material
  • Oxygen pressure
  • La0.7Sr0.3MnO3 thin film
  • Double exchange interaction
  • Pulsed laser deposition technique
  • Abstract Bismuth ferrite material (BiFeO3, BFO) exhibits ferroelectric and antiferromagnetic properties simultaneously at room temperature. It has attracted researchers to study the effect of magnetic and electric field controlled interaction between multiferroic/metallic ferromagnetic bilayer for room temperature device application.
      In this work, we are investigating La0.7Sr0.3MnO3 thin films deposition on STO(001) and STO(111) substrate at different oxygen pressure (100mtorr、200mtorr、300mtorr、400mtorr) by Pulsed Laser Deposition technique, for using it as conducting layer in BPFO/LSMO/STO system in the future..
      The results show 100mTorr thin film’s diffraction peak is shifted to lower degree than other higher oxygen pressure (200mTorr、300mTorr、400mTorr) thin films, the resistivity is higher than other sample, and the magnetization vs magnetic field measurement show that it has more than one ferromagnetic phases. It seems that this system have more oxygen vacancies than our other samples, which causes shift in diffraction peak, higher resistivity and imperfect phase (more than one ferromagnetic phases). Films deposited at higher oxygen pressure(200mTorr、300mTorr、400mTorr) are more conductive, have higher Curie Temperature (Tc=350K). These results show that thin films grown under higher oxygen pressure are better ferromagnetic conductor at room temperature. LSMO grown at STO(111) with 200mTorr oxygen pressure exhibits smallest thickness and smallest coercivity, which might be due to parallel domain alignment, that is why it has better conductive and magnetic properties.
    Advisory Committee
  • Shih-Jye Sun - chair
  • Chun-Yu Hsu - co-chair
  • Hsiung Chou - advisor
  • Files
  • etd-0731115-111753.pdf
  • Indicate in-campus at 5 year and off-campus access at 5 year.
    Date of Submission 2015-08-31

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