Magnetic sensors based on topological insulators

dc.contributor.advisor David C. Jiles
dc.contributor.author Ni, Yan
dc.contributor.department Electrical and Computer Engineering
dc.date 2018-08-11T15:55:53.000
dc.date.accessioned 2020-06-30T03:08:24Z
dc.date.available 2020-06-30T03:08:24Z
dc.date.copyright Fri Jan 01 00:00:00 UTC 2016
dc.date.embargo 2017-11-30
dc.date.issued 2016-01-01
dc.description.abstract <p>The ever-increasing demands for higher computing capabilities and low energy consumption has necessitated the developing of micro or nano electronics and sensors. This results in increasing demand for faster, higher performance, more compact and low energy consumption devices and sensors which pushes microelectronics to its physical limit. Driven by size, cost, sensitivity, reliability and power consumption, the electronic and magnetic related devices are entering a completely new age where innovations on new materials and physics are being explored. Among the most promising materials, magnetoelectric multiferroic (MEMF) and topological insulators (TI) have attracted a great deal of interest, since they are promising for their unique properties and innovative applications. The coupling of electric and magnetic properties of MEMF and the ultrahigh surface carrier mobility of TI enlighten the design of devices with extremely low thermal losses and energy cost.</p> <p>However, most of the device implementations of these material systems are still in status of ideas and laboratory prototypes. The prospects of practical realization of devices based on MEMF and TI encounter several critical challenges: the low ME coupling coefficient and current leakage in magnetoelectric(ME) sensor; fabrication large scale, low roughness and large terrace width of TI thin films for industry utilization; the high bulk conductivity and low sensitivity of TI based magnetic sensors. The present thesis will address some problems and challenges based on the above questions.</p> <p>In this work, several aspects regarding to achieve a high performance and low energy consuming devices were investigated including: systemically studied and manipulated the energy band structure of TI for nanosized electronics and sensors application; developed Hall effect sensor and anomalous Hall effect sensor based on magnetically doped topological insulator; explored a method to increase the ME coupling coefficient of ME sensors; There are nine chapters in this dissertation. Chapter 1 gives general background to readers on magnetic sensors which used widely in daily life. Basic physics of two kinds of important materials: topological insulators and MEMF composites will also be introduced. Besides that, chapter 1 will also introduce a proposed switching device which integrates both two kinds of materials. The last part of chapter 1 will be the motivation and objectives of work in this dissertation. Chapter 2 will review the experiments, techniques and equipment used for research in this dissertation including sample fabrication methods and testing methods. Starting from chapter 3, topological insulators material fabrication and sensor application will be introduced based on different kind of TIs. Study on MEMF sensors will be introduced in chapter 8. Chapter 9 is a summary of all the work and gives some general conclusions of this dissertation.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/etd/16056/
dc.identifier.articleid 7063
dc.identifier.contextkey 11337888
dc.identifier.doi https://doi.org/10.31274/etd-180810-5685
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath etd/16056
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/30239
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/etd/16056/Ni_iastate_0097E_16107.pdf|||Fri Jan 14 20:54:26 UTC 2022
dc.subject.disciplines Electrical and Electronics
dc.subject.keywords Anomalous Hall effect
dc.subject.keywords Hall effect
dc.subject.keywords magnetic sensor
dc.subject.keywords multiferroic
dc.subject.keywords thin film
dc.subject.keywords topological insulator
dc.title Magnetic sensors based on topological insulators
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication a75a044c-d11e-44cd-af4f-dab1d83339ff
thesis.degree.discipline Electrical Engineering
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
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