High frequency study of core–shell reusable CoFe2O4–ZnO nanospheres

Autor: Bijoy K. Kuanr, Armstrong M. Wilson, Sanjay R. Mishra, R. E. Camley, V. Veerakumar, Alka V. Kuanr, Zbigniew Celinski
Rok vydání: 2014
Předmět:
Zdroj: Journal of Applied Physics. 115:17B515
ISSN: 1089-7550
0021-8979
DOI: 10.1063/1.4866081
Popis: Recently, coated nanoshells combined with magnetic nanoparticles and cancer-cell-specific antibodies have been used to develop a multifunctional platform for simultaneously diagnosing and treating cancer, via magnetic resonance imaging and photothermal therapy. For this application, core-shell nano-spheres with a low resonance frequency (low GHz range) in a strong applied field are required. In this aspect, ferromagnetic resonance experiment is an important tool for determining the dynamic properties of nano-materials. Magnetic field dependence of resonance frequency (fr) and linewidths (Δƒ and ΔH) for both the ZnO coated and uncoated CoFe2O4 hollow spheres are studied using a vector network analyzer. As compared to uncoated CoFe2O4 hollow sphere, ZnO coated CoFe2O4 showed reduced resonance frequency, larger Δƒ and ΔH, reduced gyromagnetic ratio and effective fields. The experimental results are confirmed with the effective medium theory.
Databáze: OpenAIRE