Magnetic quartz crystal microbalance

In this thesis, a new technique for using quartz crystal microbalance (QCM) in magnetic field was explored. This technique would take advantage of the sensitive nature of QCM to vibration changes. The idea is to perturb the QCM vibrations with magnetic materials on it by applying magnetic field. A n...

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Main Author: Yu, George Yang
Published: Georgia Institute of Technology 2008
Subjects:
Online Access:http://hdl.handle.net/1853/24615
id ndltd-GATECH-oai-smartech.gatech.edu-1853-24615
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spelling ndltd-GATECH-oai-smartech.gatech.edu-1853-246152013-01-07T20:27:35ZMagnetic quartz crystal microbalanceYu, George YangMagneticQuartz crystal microbalanceMulti-layerGold nickel stackPolyanilineParticle suspensionProximity effectMagnetismMagneticsThin filmsQuartz crystal microbalancesQuartz crystalsMicrobalancesIn this thesis, a new technique for using quartz crystal microbalance (QCM) in magnetic field was explored. This technique would take advantage of the sensitive nature of QCM to vibration changes. The idea is to perturb the QCM vibrations with magnetic materials on it by applying magnetic field. A new instrument called magnetic QCM (MQCM) was constructed to explore this technique. The thesis contains three bodies of work. The first body describes the development of the MQCM instrument and the demonstration of the technique. The resonance frequency of a QCM with conducting polymer (polyaniline) suspension in poly(ethylene glycol) was observed to increase with increasing applied DC magnetic field. The change in population of free spins through doping with HCl vapor is reflected in increased frequency-field curve magnitude. The second body of work describes the study of QCM proximity phenomenon discovered during the MQCM instrument development process. When an object approaches a vibrating QCM, the resonant frequency changes. This proximity effect is seen at the distance of 10 mm in air and becomes more pronounced as the distance decreases. This effect depends on the value of quality factor, conductivity of the object, and electrical connection of the object to the QCM electrodes. A simple modified Butterworth van-Dyke model is used to describe this effect. It must be recognized that this effect may lead to experimental artifacts in a variety of analytical QCM applications. The third body of work describes an improved version of MQCM. The complex geometry such as particle suspension were simplified to alternating stack of ferromagnetic and diamagnetic layers. When magnetic field was applied, changes in the QCM admittance magnitude and phase curves were observed. A mass-equivalent stack of continuous consecutive layers of nickel and gold was also exposed to magnetic field but no changes were observed. Butterworth-van-Dyke model attributed the effect to internal shear friction loss among other losses is modulated by the magnetic field. Quantum effect was considered. However, after examining SEM surface images, the source of acoustic response to magnetic field is more likely from interfacial stresses.Georgia Institute of Technology2008-09-17T19:25:27Z2008-09-17T19:25:27Z2008-07-08Dissertationhttp://hdl.handle.net/1853/24615
collection NDLTD
sources NDLTD
topic Magnetic
Quartz crystal microbalance
Multi-layer
Gold nickel stack
Polyaniline
Particle suspension
Proximity effect
Magnetism
Magnetics
Thin films
Quartz crystal microbalances
Quartz crystals
Microbalances
spellingShingle Magnetic
Quartz crystal microbalance
Multi-layer
Gold nickel stack
Polyaniline
Particle suspension
Proximity effect
Magnetism
Magnetics
Thin films
Quartz crystal microbalances
Quartz crystals
Microbalances
Yu, George Yang
Magnetic quartz crystal microbalance
description In this thesis, a new technique for using quartz crystal microbalance (QCM) in magnetic field was explored. This technique would take advantage of the sensitive nature of QCM to vibration changes. The idea is to perturb the QCM vibrations with magnetic materials on it by applying magnetic field. A new instrument called magnetic QCM (MQCM) was constructed to explore this technique. The thesis contains three bodies of work. The first body describes the development of the MQCM instrument and the demonstration of the technique. The resonance frequency of a QCM with conducting polymer (polyaniline) suspension in poly(ethylene glycol) was observed to increase with increasing applied DC magnetic field. The change in population of free spins through doping with HCl vapor is reflected in increased frequency-field curve magnitude. The second body of work describes the study of QCM proximity phenomenon discovered during the MQCM instrument development process. When an object approaches a vibrating QCM, the resonant frequency changes. This proximity effect is seen at the distance of 10 mm in air and becomes more pronounced as the distance decreases. This effect depends on the value of quality factor, conductivity of the object, and electrical connection of the object to the QCM electrodes. A simple modified Butterworth van-Dyke model is used to describe this effect. It must be recognized that this effect may lead to experimental artifacts in a variety of analytical QCM applications. The third body of work describes an improved version of MQCM. The complex geometry such as particle suspension were simplified to alternating stack of ferromagnetic and diamagnetic layers. When magnetic field was applied, changes in the QCM admittance magnitude and phase curves were observed. A mass-equivalent stack of continuous consecutive layers of nickel and gold was also exposed to magnetic field but no changes were observed. Butterworth-van-Dyke model attributed the effect to internal shear friction loss among other losses is modulated by the magnetic field. Quantum effect was considered. However, after examining SEM surface images, the source of acoustic response to magnetic field is more likely from interfacial stresses.
author Yu, George Yang
author_facet Yu, George Yang
author_sort Yu, George Yang
title Magnetic quartz crystal microbalance
title_short Magnetic quartz crystal microbalance
title_full Magnetic quartz crystal microbalance
title_fullStr Magnetic quartz crystal microbalance
title_full_unstemmed Magnetic quartz crystal microbalance
title_sort magnetic quartz crystal microbalance
publisher Georgia Institute of Technology
publishDate 2008
url http://hdl.handle.net/1853/24615
work_keys_str_mv AT yugeorgeyang magneticquartzcrystalmicrobalance
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