Speaker
Tayyaba Firdous
(Department of Physics, University of Alberta, T6G 2E1, Canada)
Description
Magnetic properties for isolated and small-scale assemblies of nanoparticles are generally derived from measurements of bulk nanoparticle systems. To complement this, we aim to investigate these properties for individual assemblies of single-domain magnetite nanoparticles.
Nanoparticles, ~ 50 nm in size and harvested from magnetotactic bacteria, were deposited by Nano eNnabler (BioForce Nanosciences TM) on a 100 nm thick, high stress Si3N4 membrane 40 × 200 μm in size. The nanoparticles form diverse patterns on the membrane, including aggregates influenced by dipolar coupling. To capture select structures for measurement, nanomechanical torsional resonators are fabricated in the membrane by direct writing with a focused ion beam. Magnetic measurements are obtained by nanomechanical torque magnetometry, a sensitive method to probe the quasi-static magnetization response.
The observations are compared to micromagnetic modeling of the hysteresis of a specific measured cluster of ~ 350 nanoparticles, and to numerical simulations of the mechanical modes.
Primary author
Tayyaba Firdous
(Department of Physics, University of Alberta, T6G 2E1, Canada)
Co-authors
Aidan McDermott
(Department of Physics, University of Alberta, T6G 2E1, Canada)
David Potter
(Department of Physics, University of Alberta, T6G 2E1, Canada)
Dennis Bazylinski
(School of Life Sciences, University of Nevada at Las Vegas, NV 89154, USA)
Doug Vick
(National Institute of Nanotechnology, T6G 2M9, Canada)
Fatemeh Fani Sani
(Department of Physics, University of Alberta, T6G 2E1, Canada)
Joe Losby
(Department of Physics, University of Alberta, T6G 2E1, Canada)
Mark Freeman
(Department of Physics, University of Alberta, T6G 2E1, Canada)
Miroslav Belov
(National Institute of Nanotechnology, T6G 2M9, Canada)
Tanya Prozorov
(US DOE Ames Laboratory, Ames, IA 50011, USA)
