Characterizing and imaging magnetic nanoparticles by optical magnetometry

7th International Symposium and Young Scientists School "Modern Problems of Laser Physics"

Weis, A.^1 ; Colombo, S.^1 ; Dolgovskiy, V.^1 ; Gruji, Z.D.^1 ; Lebedev, V.^1 ; Zhang, J.^1

Physics Department, University of Fribourg, Chemin du Musée 3, Fribourg

1700, Switzerland^1

关键词: Anisotropy constants;    Atomic magnetometers;    Biomedical imaging;    Direct measurement;    Magnetic nanoparticles;    Magnetic particle imaging;    Optical magnetometers;    Optical magnetometry;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/793/1/012032/pdf
DOI  :  10.1088/1742-6596/793/1/012032

来源: IOP

【 摘 要 】

We review our ongoing work on deploying optical (atomic) magnetometry for measuring the magnetic response of magnetic nanoparticle (MNP) samples, yielding MNP size distributions, and other sample parameters like Néel relaxation time τ, saturation magnetisation Ms, anisotropy constant K and magnetic susceptibility χ. We address magnetorelaxation (MRX) signals, in which the decaying magnetisation M(t) following a magnetising pulse is recorded by a single atomic magnetometer or by a novel magnetic source imaging camera (MSIC) allowing spatially resolved MRX studies of distributed MNP samples. We further show that optical magnetometers can be used for a direct measurement of the M(H) and dM/dH(H) dependencies of MNP samples, the latter forming the basis for an optical magnetometer implementation of the MPI (Magnetic Particle Imaging) method. All experiments are in view of developing biomedical imaging modalities.