Nanomechanical and Optomechanical Torque Magnetometry of Isolated Nanomagnetic Assemblies

• Author / Creator

  Firdous, Tayyaba

• Nanomechanical torque magnetometry is emerging as a highly-sensitive method for gauging magneto-statics and magnetic dynamics in mesoscopic and nano-scale magnetic materials. Advances in torque magnetometry are presented here, which were unattainable using previ- ous techniques. Silicon nitride membrane-based nanomechanical torque magnetometers were first fabricated and characterized using the resonance modes and magnetic hysteresis and integrated with ∼ 350 bacterial magnetosome nanoparticles in a random assembly. Methods of assembling the magnetic materials (nanoparticles, mesoscopic magnetic disks) in geometrical shapes on the nanomechanical torque magnetometers were developed later on. Further, optomechanical torque magnetometers were developed to derive their highly sensitive transductions in ambient conditions. Optomechanical torque magnetometers were also used as RF susceptometers to acquire the vector-based susceptibility components. Finally, RF susceptometry was combined with the torque-mixing resonance spectroscopy for characterization of magnetic dynamics. The new nanophotonic optomechanical torque magnetometers developed in this Thesis can potentially be used for probing the magnetization, susceptibility, and spin resonances in a countable number of magnetic nanoparticles, leading to single spin detection in ambient conditions.

• Subjects / Keywords

  • Nanomechanical
  • Nanoparticles
  • Assemblies
  • Yttrium-iron-garnet
  • Optomechanical
  • High-sensitivity
  • Devices
  • Torque
  • Magnetometers
  • Resonators
  • Susceptometers

• Graduation date

  Fall 2018

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3T14V52Q

• License

  Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.