Full metadata record
DC Field | Value | Language |
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dc.contributor.advisor | 김철기 | - |
dc.contributor.author | Amir Aly Ibrahim Elzawawy | - |
dc.date.accessioned | 2019-08-22T16:00:40Z | - |
dc.date.available | 2019-08-22T16:00:40Z | - |
dc.date.issued | 2019 | - |
dc.identifier.uri | http://dgist.dcollection.net/common/orgView/200000217242 | en_US |
dc.identifier.uri | http://hdl.handle.net/20.500.11750/10459 | - |
dc.description | Sensors | - |
dc.description.statementofresponsibility | prohibition | - |
dc.description.tableofcontents | Abstract -------------------------------------------------------------------------------------------------- i Acknowledgment -------------------------------------------------------------------------------------- iii Table of contents ---------------------------------------------------------------------------------------- v List of figures ------------------------------------------------------------------------------------------ viii List of tables --------------------------------------------------------------------------------------------- x List of abbreviations ----------------------------------------------------------------------------------- xi Outline of the thesis ----------------------------------------------------------------------------------- xii I. Introduction ------------------------------------------------------------------------------------------ 1 1.1 Exchange bias in FM/AFM bilayers ------------------------------------------------------------- 1 1.1.1 FM layer material and thickness effect ---------------------------------------------------- 3 1.1.2 AFM layer material and thickness effect -------------------------------------------------- 3 1.1.3 Interface roughness effect ------------------------------------------------------------------- 4 1.1.4 Seed layer effect ------------------------------------------------------------------------------ 4 1.1.5 Capping layer effect -------------------------------------------------------------------------- 5 1.2 Exchange bias in FM/NM/AFM trilayers: spacer layer material and thickness effect ---- 5 1.3 Magnetoresistance and planar Hall effect ------------------------------------------------------- 5 1.4 Planar Hall effect sensors: operating field range, output voltage, and shunt current ------ 6 1.4.1 PHE sensors without exchange bias in NiFe single layer ------------------------------- 7 1.4.2 PHE sensors with exchange bias in NiFe/IrMn bilayer --------------------------------- 9 1.4.3 PHE sensors with exchange bias in NiFe/Spacer/IrMn trilayer ------------------------ 13 1.5 Sensitivity of planar Hall effect sensors --------------------------------------------------------- 16 1.6 Noise in magnetoresistance sensors -------------------------------------------------------------- 16 1.6.1 Barkhausen noise ----------------------------------------------------------------------------- 16 1.6.2 Thermal noise --------------------------------------------------------------------------------- 17 1.6.3 1/f noise ---------------------------------------------------------------------------------------- 17 1.6.4 Reduction of noise by optimization of layer composition and sensors shape -------- 17 II. Experimental techniques ------------------------------------------------------------------------- 19 2.1 Materials --------------------------------------------------------------------------------------------- 19 2.2 Samples fabrication -------------------------------------------------------------------------------- 19 2.2.1 Photolithography method -------------------------------------------------------------------- 19 2.2.1.1 Optimization of UV exposure time and developing time ------------------------- 23 2.2.2 Lift off method -------------------------------------------------------------------------------- 24 2.2.3 DC magnetron sputtering system ----------------------------------------------------------- 24 2.2.3.1 Characterization of deposition rate --------------------------------------------------- 24 2.2.3.2 Adjustment of sample location on the sample holder with the built in magnet - 25 2.2.4 Sensor deposition ----------------------------------------------------------------------------- 28 2.2.5 Electrode deposition -------------------------------------------------------------------------- 28 2.3 Samples characterization -------------------------------------------------------------------------- 29 2.3.1 Planar Hall effect measurements ------------------------------------------------------------ 29 2.3.2 Vibrating sample magnetometry (VSM) --------------------------------------------------- 30 2.3.3 Noise measurements ------------------------------------------------------------------------- 30 2.3.4 Atomic force microscopy (AFM) ---------------------------------------------------------- 31 2.3.5 High resolution transmission electron microscopy (HR-TEM) ------------------------ 32 2.3.6 X-ray diffraction spectroscopy (XRD) ---------------------------------------------------- 32 III. Tailoring of exchange bias by material and thickness variation of seed layer ------- 33 3.1 Hybrid seed layer material and thickness effects on crystallinity and growth direction of FM and AFM layers for NiFe/IrMn bilayer---------------------------------------------------------- 33 3.2 Ta/Cu and Ta/Au hybrid seed layer effects on the exchange bias with NiFe/IrMn bilayer --------------------------------------------------------------------------------------------------------------- 39 3.3 NiFeCr seed layer effects on the exchange bias field in NiFe/Au/IrMn trilayer ----------- 40 IV. Interlayer material effects for the multilayer structures --------------------------------- 44 4.1 Effect of the NM interlayer material on the parameters of magnetic hysteresis loop for NiFe/NM/NiFe trilayers ------------------------------------------------------------------------------- 44 4.2 NiFeCr as a spacer layer in NiFe/Spacer/IrMn trilayer --------------------------------------- 48 V. Capping layer material effects on the exchange bias for multilayer structures ------- 49 5.1 NiFeCr capping layer effects on the exchange bias field in NiFe/Au/IrMn trilayer ------- 49 VI. Effect of active layers on sensor’s output voltage, operating field range, sensitivity and noise in multilayer structures ----------------------------------------------------------------- 51 6.1 NiFeCr as an active FM layer and AFM in comparison with NiFe/IrMn bilayer structure --------------------------------------------------------------------------------------------------------------- 51 6.2 Magnetic field sensitivity of PHE sensors, based on NiFe/Au/IrMn trilayer junctions, grown with Ta and NiFeCr seed and capping layers -------------------------------------------------------- 52 6.3 Optimization of sensitivity by material and thickness variation of FM layer in FM/IrMn bilayer ---------------------------------------------------------------------------------------------------- 57 6.4 Untethered operating field range adjustment by interdependent variation of non-magnetic spacer and capping layers thicknesses ---------------------------------------------------------------- 67 6.5 Magnetoresistance response in sweeping magnetic field for NiFe/NM/NiFe trilayer ----- 73 6.6 Uncorrelated responses of PHE and AMR to Barkhausen jumps in sweeping magnetic field for NiFe/NM/NiFe trialyer ----------------------------------------------------------------------------- 77 6.7 The planar Hall voltage noise in stationery magnetic field for NiFe/NM/NiFe trialyer --- 82 Conclusions and perspectives ----------------------------------------------------------------------- 87 List of publications ------------------------------------------------------------------------------------ 93 List of conferences ------------------------------------------------------------------------------------- 94 Summer school and internship ---------------------------------------------------------------------- 97 References ---------------------------------------------------------------------------------------------- 98 |
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dc.format.extent | 120 | - |
dc.language | eng | - |
dc.publisher | DGIST | - |
dc.source | /home/dspace/dspace53/upload/200000217242.pdf | - |
dc.title | Fabrication and optimization of magnetoresistive thin film structure for improved spintronic sensors | - |
dc.title.alternative | 향상된 스핀 트로닉스 센서를위한 자기 저항 박막 구조 제작 및 최적화 | - |
dc.type | Thesis | - |
dc.identifier.doi | 10.22677/thesis.200000217242 | - |
dc.description.degree | Doctor | - |
dc.contributor.department | Department of Emerging Materials Science | - |
dc.contributor.coadvisor | Hyeon-Jun Lee | - |
dc.date.awarded | 2019-08 | - |
dc.publisher.location | Daegu | - |
dc.description.database | dCollection | - |
dc.citation | XT.MD 아38 201908 | - |
dc.date.accepted | 2019-07-01 | - |
dc.contributor.alternativeDepartment | 신물질과학전공 | - |
dc.embargo.liftdate | 2024-06-30 | - |
dc.contributor.affiliatedAuthor | Kim, CheolGi | - |
dc.contributor.affiliatedAuthor | Elzawawy, Amir Aly Ibrahim | - |
dc.contributor.affiliatedAuthor | Lee, Hyeon-Jun | - |
dc.contributor.alternativeName | 이현준 | - |
dc.contributor.alternativeName | CheolGi Kim | - |
dc.contributor.alternativeName | 아미르 | - |
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