Title:
Magnetic quartz crystal microbalance

dc.contributor.advisor Janata, Jiří
dc.contributor.advisor Hunt, William D.
dc.contributor.author Yu, George Yang en_US
dc.contributor.committeeMember Allen, Mark
dc.contributor.committeeMember Brand, Oliver
dc.contributor.committeeMember Ferguson, Ian
dc.contributor.committeeMember Lyon, Anew
dc.contributor.department Electrical and Computer Engineering en_US
dc.date.accessioned 2008-09-17T19:25:27Z
dc.date.available 2008-09-17T19:25:27Z
dc.date.issued 2008-07-08 en_US
dc.description.abstract 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. en_US
dc.description.degree Ph.D. en_US
dc.identifier.uri http://hdl.handle.net/1853/24615
dc.publisher Georgia Institute of Technology en_US
dc.subject Magnetic en_US
dc.subject Quartz crystal microbalance en_US
dc.subject Multi-layer en_US
dc.subject Gold nickel stack en_US
dc.subject Polyaniline en_US
dc.subject Particle suspension en_US
dc.subject Proximity effect en_US
dc.subject.lcsh Magnetism
dc.subject.lcsh Magnetics
dc.subject.lcsh Thin films
dc.subject.lcsh Quartz crystal microbalances
dc.subject.lcsh Quartz crystals
dc.subject.lcsh Microbalances
dc.title Magnetic quartz crystal microbalance en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.advisor Hunt, William D.
local.contributor.advisor Janata, Jiří
local.contributor.corporatename School of Electrical and Computer Engineering
local.contributor.corporatename College of Engineering
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