SQUID-Based Relaxometric Diagnostics of Magnetic Nanoparticles

Ivan Volkov; Oleg Snigirev; Alexander Maresov; Alexander Volkov; Yasukuni Torii; Saburo Tanaka

doi:10.4028/www.scientific.net/SSP.152-153.217

Paper Titles

Effect of Surfactant Excess in Non-Polar Ferrofluids Probed by Small-Angle Neutron Scattering
p.198

Synthesis and Effect of Some Parameters through Reverse Micelles Route of Iron Oxide Nanoparticles
p.205

Magnetic Structure of Fe/V Superlattices with Variable Thickness of Iron Layers
p.209

Effect of Interaction in the Magnetization Reversal Relaxation of Superparamagnetic Granular CoFeB -SiO₂ Films
p.213

SQUID-Based Relaxometric Diagnostics of Magnetic Nanoparticles
p.217

Nanostructures Based on Glasses Doped with 3d and 4f Elements
p.221

Dynamics of Magnetization in Frustrated Spin-Chain Systems: Ca₃Co₂O₆
p.225

Magnetic, Thermal and Transport Properties of High-Pressure Synthesized Nanocrystalline EuC₆
p.229

Magnetic Phase Diagram and Magnetization Dynamics of Frustrated Spin-Chain Compounds
p.233

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SQUID-Based Relaxometric Diagnostics of Magnetic Nanoparticles

Abstract:

The method of SQUID-based relaxometric diagnostics has been applied to the ensembles of non-interacting near-spherical Fe3O4 and Co nanoparticles in order to reveal the behavior of the anisotropy constant upon varying the molecular surrounding of nanoparticles by using different polymer matrices. The transmission electron microscopy (TEM) and X-ray diffraction techniques have been employed to obtain the structural information about objects of study. The relaxation curves measured with the SQUID-relaxometer in the time range from about 50 s to several tens of seconds after application of a pulse of low dc magnetizing field have been approximated by theoretical dependences calculated within the framework of activation Néel–Arrhenius law with account for the size distribution functions retrieved from TEM data. From results of approximations, the values of anisotropy constant have been determined.