<p> I discuss the design and operation of a system for levitating a charged, μm-scale, multilayer graphene nanoplatelet in a quadrupole electric field trap in high vacuum. Levitation decouples the platelet from its environment and enables sensitive mechanical and magnetic measurements. </p><p> First, I describe a method of generating and trapping the nanoplatelets. The platelets are generated via liquid exfoliation of graphite pellets and charged via electrospray ionization. Individual platelets are trapped at a pressure of several hundred mTorr and transferred to a trap in a second chamber, which is pumped to UHV pressures for further study. All measurements of the trapped platelet's motion are performed via optical scattering. </p><p> Second, I present a method of gyroscopically stabilizing the levitated platelet. The rotation frequency of the platelet is locked to an applied radio frequency (rf) electric field <i><b>E</b></i><sub>rf</sub>. Over time, frequency-locking stabilizes the platelet so that its axis of rotation is normal to the platelet and perpendicular to <i><b>E</b></i><sub> rf</sub>. </p><p> Finally, I present optical data on the interaction of a multilayer graphene platelet with an applied magnetic field. The stabilized nanoplatelet is extremely sensitive to external torques, and its low-frequency dynamics are determined by an applied magnetic field. Two mechanisms of interaction are observed: a diamagnetic polarizability and a magnetic moment proportional to the frequency of rotation. A model is constructed to describe this data, and experimental values are compared to theory.</p><p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:10641221 |
| Date | 14 March 2018 |
| Creators | Coppock, Joyce Elizabeth |
| Publisher | University of Maryland, College Park |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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