Systematic Study of Parameters Affecting Unconventional Magnetism in Gold Nanostructures

Dong, Pengcheng

Systematic Study of Parameters Affecting Unconventional Magnetism in Gold Nanostructures

dc.contributor.advisor	Trudel, Simon
dc.contributor.author	Dong, Pengcheng
dc.contributor.committeemember	Salahub, Dennis R.
dc.contributor.committeemember	Sutherland, Todd C.
dc.contributor.committeemember	Bryant, Steven L.
dc.contributor.committeemember	Leznoff, Daniel B.
dc.date	2018-06
dc.date.accessioned	2018-03-15T20:12:27Z
dc.date.available	2018-03-15T20:12:27Z
dc.date.issued	2018-03-09
dc.description.abstract	In this exploratory study we seek to make sense of the conflicting results and interpretations of the novel magnetism of gold, by isolating two variables for testing. They are molecular dipole moment of the thiol that forms a self-assembled monolayer (SAM) on gold nanoparticles and thin-films, and roughness of gold thin-films. The first variable is chosen because the dipole moment of the thiol is believed to affect the ease of charge redistribution from gold to the SAM. The second variable is studied because the domain size of the SAM has been suggested to influence the magnetism of coated gold surfaces, and because nanostructuring of gold could be a source of magnetism itself. In this thesis we study a series of gold nanoparticles coated by different thiols, a series of flat gold thin-films coated by different alkanethiols, and finally, a series of highly porous gold thin-films, which can also be coated by thiols. The first series shows that magnetism of Au NPs does relate to the thiol used to coat it, and that the effect of an electron-withdrawing terminal group of the thiol is much greater than its chain length. The second series establishes that thiolate-coated gold thin-films are indeed magnetic, a notion previously debated. It shows the thin-films to be soft ferromagnets, with evidence emerging for the existence of ferromagnetic exchange in them. The third series finds highly anisotropic magnetization in thiolate-coated nanoporous gold, and shows that the nanoporous gold to be not only magnetic without any coating, but to display magneto-optical Kerr effect as well, which proves the existence of spin polarization in the nanoporous gold. In order to create novel gold nanostructures, low-potential anodization of gold in oxalic acid is studied with the goal of deducing mechanism and improving applicability. Oxalic acid is shown not to be the uniquely suitable electrolyte, with the finding of hydroquinone as a replacement, offering support to our model involving a gold complex participating in catalysis.	en_US
dc.identifier.citation	Dong, P. (2018). Systematic study of parameters affecting unconventional magnetism in gold nanostructures (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/31097	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/31097
dc.identifier.uri	http://hdl.handle.net/1880/106437
dc.language.iso	eng
dc.publisher.faculty	Graduate Studies
dc.publisher.faculty	Science
dc.publisher.institution	University of Calgary	en
dc.publisher.place	Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	nanoparticle
dc.subject	magnetism
dc.subject	gold
dc.subject	thin-film
dc.subject	thiol
dc.subject.classification	Education--Sciences	en_US
dc.title	Systematic Study of Parameters Affecting Unconventional Magnetism in Gold Nanostructures
dc.type	doctoral thesis
thesis.degree.discipline	Chemistry
thesis.degree.grantor	University of Calgary
thesis.degree.name	Doctor of Philosophy (PhD)
ucalgary.item.requestcopy	true
ucalgary.thesis.checklist	I confirm that I have submitted all of the required forms to Faculty of Graduate Studies.	en_US