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Colloidal Nanomagnets Developed with Strong Liquid-Phase AC Field Response for Remote 3D Imaging and Thermometry

ORAL

Abstract

Colloidal nanomagnets (CNMs) are an exciting class of material being investigated for use in a host of remote therapeutic and diagnostic modalities such as magnetic particle imaging and hyperthermia.1 These applications exploit the unique soft magnetic properties that manifest when the size of these crystals is confined to the nanoscale, specifically a strong response to applied alternating current (AC) magnetic fields while simultaneously remaining dispersed in liquid media. CNMs, which are often solution-synthesized ferrites, also frequently display a temperature-dependent magnetization that may be employed for thermometry. Here, we unveil a series of CNMs specifically developed for use in AC magnetic field-based remote imaging and thermometry. Careful selection of the synthetic reagents and precursor thermal decomposition kinetics2 allow for control of the resultant CNM composition (Fe, Co, Zn, V ratios) and size (5-80 nm). By tuning these variables, as confirmed by spectroscopy, scattering, and microscopy, we can then use frequency-, amplitude-, and temperature-dependent magnetometry to reveal their commensurate AC field response. In this way, we correlate CNM structure to performance and conclude by expounding guidelines to govern our use of CNMs for magnetic imaging and thermometry.

[1] Shasha and Krishnan Adv. Mater., 33, 1904131 (2021)

[2] Biacchi et al. Chem. Mater., 34, 2907-2918 (2022)

[3] Bui et al. J. Appl. Phys., 128, 224901 (2020); Bui et al. Appl. Phys. Lett., 120, 012407 (2022)

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Publication: Biacchi et al. Chem. Mater., 34, 2907-2918 (2022)<br>Bui et al. Appl. Phys. Lett., 120, 012407 (2022)<br>Biacchi et al. Int. J. Magn. Part. Imaging, 6, 2 Suppl 1 (2020)<br>Bui et al. J. Appl. Phys., 128, 224901 (2020)<br>Biacchi et al. "Size-Mediated Tuning of AC/DC Magnetic Properties in Ferrite Iron Oxide Nanocrystal Powders and Colloidal Ferrofluids" in preparation for submission to Advanced Functional Materials<br>Abel et al. "Thermosensitivity Through Exchange Coupling in Ferrimagnetic/Antiferromagnetic Nano-objects" in preparation for submission to J. Appl. Phys.<br>

Presenters

  • Adam Biacchi

    National Institute of Standards and Technology (NIST), National Institute of Standards and Technology

Authors

  • Adam Biacchi

    National Institute of Standards and Technology (NIST), National Institute of Standards and Technology

  • Thinh Q Bui

    National Institute of Standards and Tech

  • Frank M Abel

    National Institute of Standards and Technology

  • Eduardo L Correa

    National Institute of Standards and Technology (NIST), National Institute of Standards and Technology

  • Samuel D Oberdick

    National Institute of Standards and Technology (NIST), National Institute of Standards and Technology & University of Colorado, Boulder, University of Colorado, Boulder

  • Curt A Richter

    National Institute of Standards and Tech, Nanoscale Device Characterization Division, National Institute of Standards and Technology

  • Cindi L Dennis

    National Institute of Standards and Technology (NIST), National Institute of Standards and Technology

  • Solomon I Woods

    National Institute of Standards and Tech

  • Angela R Hight Walker

    National Institute of Standards and Tech, National Institute of Standards and Technology