Magneto-optic Characterization of Super Paramagnetic (SP) Nanoparticles
Team
Dr. Maarij Syed Dr. Syed Azer Reza
Professor, Department of Physics & Associate Professor of Physics &
Optical Engineering Optical Engineering
Haoxiang Lu William Amory
Undergraduate Student Undergraduate Student
Optical Engineering Optical Engineering
Charlie (Chong-Yi)
Undergraduate Student
Motivation
SP nanoparticles are used in various applications ranging from drug delivery, a contrast dye in MRI imaging, to DNA/RNA purification and cancer hyperthermia therapy. This pervasive use and very promising future use cases of SP nanoparticles, as well as our expertise, motivated us toward finding ways to better understand SP nanoparticles behavior and eventually model it better and characterize these properties using measurements with enhanced sensitivity.
Under Creative Commons License, reproduced from Elsevier Nedylakova, Miroslava et.al. "Iron oxide magnetic aggregates: Aspects of synthesis, computational approaches and applications." Advances in Colloid and Interface Science (2023): 103056.
Our Work
Our research since 2023 has been focused primarily on the development of sensitive experimental methods to characterize SP nano-particle responses, studying the effects of environmental and control factors as well as developing theoretical models to describe the linear and non-linear magneto-optic response exhibited by various different SP nanoparticle samples.
Exploring Experimental Configurations
We recently demonstrated experimentally [a,b] that the non-linear spectral response to an input optical signal of the magneto-optic nanoparticle samples placed in AC magnetic fields is governed by various factors. One of this is the optical configuration that is used for the measurements. We are further exploring this aspect by developing novel experimental testbeds to study the spectral output of the recorded irradiance signals.
Studying Effects of External Variables
There are various other factors that affect spectral response of samples – some drastically and other so as much. These includes studying the effect of temperature, particle concentration, particle type, applied magnetic field amplitude and frequency as well as the amplitude of the input optical signal.
Developing Theoretical Models
Another direction which our work is geared towards is the development of mathematical models to better predict the non-linear magnetization effects that manifest as a non-linear Faraday rotation in magneto-optic nanoparticles. This is key to understanding the harmonic decomposition of the received signal with a photodetector as these nonlinearities embed into these optical irradiance measurements. The work focuses on identifying the reasons for the appearance of harmonic peaks from basic measurement configuration geometries to non-linear magnetization effects which may arise to nanoparticle interactions and the morphology of their possible aggregations.
Publications
Our collaboration has resulted in some exciting preliminary results which have been shared with the scientific community in the form of following papers/presentations in some of the top journals and conferences.
[a] Syed, S. A. Reza, P. D. Miller, and B. Roop, “Magneto-Optical Characterization of TCO Films using Standard and Enhanced Cavity Configurations,” AIP Advances 14(2), 2024. https://doi.org/10.1063/9.0000751
[b] D. Miller, and B. Roop, M. Syed, and S. A. Reza, “Multi configuration characterization of complex magneto-optic nanoparticle response,” in SPIE Optics + Photonics, San Diego, 2024. (Invited Speaker)
[c] D. Miller, and B. Roop, M. Syed, and S. A. Reza, “Higher Harmonic Magnetic Nanoparticle Characterization using AC Faraday Rotation,” in APS March Meeting, Minnesota 2024. (Poster)
[d] B. Roop, P. D. Miller, M. Syed, and S. A. Reza, “Magnetic Nanoparticle Characterization using AC Faraday Rotation,” in APS March Meeting, Minnesota 2024. (Poster)
[e] M. Syed, S. A. Reza, P. D. Miller, and B. Roop, “Magneto Optical Characterization of TCO Films using Standard and Enhanced Cavity Configurations,” in IEEE Magnetics and Magnetic Materials Conference, Dallas 2023. (Poster)
[f] C. Brelage, M. Syed, and S.A. Reza, “Resonant Cavity Design for Enhanced Magneto Optic Measurements,” in SPIE Optics + Photonics, San Diego, 2023. (Poster)