林敏聰臺灣大學：物理研究所戴榮吉Tai, Jung-ChiJung-ChiTai2007-11-262018-06-282007-11-262018-06-282007http://ntur.lib.ntu.edu.tw//handle/246246/54470我們嘗試去組裝以有機分子或高分子為位障的磁性穿隧接面。我們用了四種方法去形成有機薄膜，其中有兩種方法成功得製備穿隧接面。此二方法是形成兩性分子的Langmuir-Blodgett (LB)膜和以旋轉塗布法製備高分子薄膜。本實驗的目標是實現在有機接面觀測到穿隧磁阻效應(TMR)，並且量測此有機磁性穿隧接面的電性、磁性、表面特性和化學性質。對於以Langmuir-Blodgett (LB)膜為位障的有機磁性穿隧接面，我們發現和磁性組態一致的穿隧磁阻效應。除此之外，我們比較了有機磁性穿隧接面在不同溫度和不同分子層下的穿隧磁阻效應。We try to fabricate magnetic tunnel junctions with the organic spacer of molecules or polymers. There are four methods we use to form organic thin layer, and two of them could successfully be used to prepare tunnel junctions. They are the method of formation of Langmuir-Blodgett (LB) films of amphibious small molecules and the method of spin coating of polymers. The main goal of the experiments is to realize the tunnel magneto-resistance (TMR) effect in the organic junction, and to measure the electric, magnetic, surface, and chemical properties of the organic magnetic tunnel junction (OMTJ). We find the tunnel magneto-resistance effect of the organic magnetic tunnel junction with the organic spacer of Langmuir-Blodgett (LB) film, which is consistent with the magnetic configuration. In addition, we compare the TMR effect at different temperature and with different molecular layers.1. Introduction and Motivation……………………………………………1 2. Apparatuses and Chemicals……………………………………………4 2.1. System of preparation 2.1.1. Sputtering system in ultrahigh vacuum 2.1.2. Preparation system of Langmuir-Blodgett films 2.1.3. Spin coating system 2.2. System of analysis 2.2.1. Electric properties 2.2.2. Magnetic properties 2.2.3. Morphology and thickness 2.2.4. Chemical properties 2.3. Chemicals and Materials A. Ferromagnetic material B. Pi-conjugated small molecules C. Semiconducting polymers D. Amphibious molecules E. Other chemicals 3. Experimental processes………………………………………………12 3.1. Preparation of ferromagnetic thin films 3.2. Preparation of organic spacer 3.2.1. Organic spacer of Langmuir-Blodgett films 3.2.2. Polymeric spacer 3.3. Analysis of samples A. Electric properties B. Magnetic properties C. Thickness D. Morphology E. Chemical properties 4. Results and Discussion………………………………………………15 4.1. Morphology of Ferromagnetic layers 4.2. Failure of the methods using electrodeposition and direct synthesis 4.3. The tunnel junctions with polymeric spacer using spin coating 4.4. The magnetic tunnel junction using LB film as spacer 4.4.1. Surface Pressure of Langmuir-Blodgett films 4.4.2. Morphology of Langmuir-Blodgett films 4.4.3. Successfully fabricating tunnel junction 4.4.4. Observation of TMR effect of 2 ML-LB MTJ 4.4.5. TMR effect of 2 ML-LB MTJ at different temperature 4.4.6. TMR effect of 1 ML-LB MTJ 4.4.7. Comparison with other report about metal-SAM-metal 4.4.8. Comparison with other report about MTJ using SAM spacer A. The spinvalve using pore-assistant SAM spacer B. The spinvalve using LB film and UV-lithography 5. Conclusion and future work…………………………………………34 5.1. Future work of MTJ with LB film spacer 5.1.1. Electric properties of tunnel junction using LB film A. Current-Voltage curve of MTJ B. Different electrodes C. Different SAM or embedded molecules 5.1.2. TMR effect of MTJ with LB film spacer A. TMR effect at different temperature and bias B. MTJ with different monolayer of LB film C. Determination of Thickness D. Component of MTJ E. Different molecular structure or Embedded-molecules 5.2. Improvement of the methods to fabricate MTJ with organic spacer A. Protecting layer or Ferrimagnetic layer B. Post-Annealing of MTJ with organic spacer 6. References1889174 bytesapplication/pdfen-US分子自旋電子學分子電子學有機磁性穿隧接面有機自旋閥穿隧磁阻LB膜Molecular SpintronicsMolecular ElectronicsOrganic Magnetic Tunnel JunctionOrganic SpinvalveTunnel MagnetoresistanceLangmuir-Blodgett filmthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/54470/1/ntu-96-R94222068-1.pdf