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Design and validation of magnetic particle spectrometer for characterization of magnetic nanoparticle relaxation dynamics

The design and validation of a magnetic particle spectrometer (MPS) system used to study the linear and nonlinear behavior of magnetic nanoparticle suspensions is presented. The MPS characterizes the suspension dynamic response, both due to relaxation and saturation effects, which depends on the mag...

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Detalles Bibliográficos
Autores principales: Garraud, Nicolas, Dhavalikar, Rohan, Maldonado-Camargo, Lorena, Arnold, David P., Rinaldi, Carlos
Formato: Online Artículo Texto
Lenguaje:English
Publicado: AIP Publishing LLC 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5336471/
https://www.ncbi.nlm.nih.gov/pubmed/28344854
http://dx.doi.org/10.1063/1.4978003
Descripción
Sumario:The design and validation of a magnetic particle spectrometer (MPS) system used to study the linear and nonlinear behavior of magnetic nanoparticle suspensions is presented. The MPS characterizes the suspension dynamic response, both due to relaxation and saturation effects, which depends on the magnetic particles and their environment. The system applies sinusoidal excitation magnetic fields varying in amplitude and frequency and can be configured for linear measurements (1 mT at up to 120 kHz) and nonlinear measurements (50 mT at up to 24 kHz). Time-resolved data acquisition at up to 4 MS/s combined with hardware and software-based signal processing allows for wide-band measurements up to 50 harmonics in nonlinear mode. By cross-calibrating the instrument with a known sample, the instantaneous sample magnetization can be quantitatively reconstructed. Validation of the two MPS modes are performed for iron oxide and cobalt ferrite suspensions, exhibiting Néel and Brownian relaxation, respectively.