Simple and fast evaluation of relaxation parameters of magnetic nanoparticles

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:499

Article

Lemal, Philipp¹  Balog, Sandor¹  Ackermann-Hirschi, Liliane¹  Taladriz-Blanco, Patricia¹  Hirt, Ann M.²  Rothen-Rutishauser, Barbara¹  Lattuada, Marco³  Petri-Fink, Alke^1,3 

[1] Univ Fribourg, Adolphe Merkle Inst, Chemin Verdiers 4, CH-1700 Fribourg, Switzerland

[2] Swiss Fed Inst Technol, Inst Geophys, Sonneggstr 5, CH-8092 Zurich, Switzerland

[3] Univ Fribourg, Chem Dept, Chemin Musee 9, CH-1700 Fribourg, Switzerland

关键词: Magnetic nanoparticles;    Magnetic hyperthermia;    Nanoparticle characterization;    Neel relaxation;    Magnetocrystalline anisotropy;   

DOI  :  10.1016/j.jmmm.2019.166176

来源: Elsevier

【 摘 要 】

The efficacy of magnetic hyperthermia treatment depends on the optimal available magnetic nanoparticles (MNPs) that are excited in a given alternating magnetic field and viscosity of the region of interest. In this regard, assessing the relevant relaxation parameters is of upmost importance and could improve the speed of development of efficient applications. Here, we demonstrate how to deduce all relevant magnetic parameters from fast, independent, and simple experimental measurements such as dynamic light scattering, vibrating sample magnetometer, and lock-in thermography. We study the thermal behaviour of two MNPs with different forms, i.e. spherical and cubical, synthesized in-house by thermal decomposition and coated with 4 different surface agents. By determination of specific absorption rate (SAR) values, hydrodynamic diameters and M- H curves it is possible to compute the magnetic particle volume, dominant relaxation time and magnetocrystalline anisotropy constant. The calculated SAR values derived from these parameters, show good agreement with the experimental determined SAR data, demonstrating the applicability of the reported procedure. Additionally, our results indicate that surface coatings can have minor impacts on the thermal dissipation of Neel relaxation dominated MNPs.

【 授权许可】

Free