title: Design and validation of magnetic particle spectrometer for characterization of magnetic nanoparticle relaxation dynamics.
abstract: 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.
authors.affiliation: Department of Electrical and Computer Engineering, University of Florida , Gainesville, Florida 32608, USA.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Garraud
authors.affiliation: Department of Chemical Engineering, University of Florida , Gainesville, Florida 32608, USA.
authors.forename: Rohan
authors.initials: R
authors.lastname: Dhavalikar
authors.affiliation: Department of Chemical Engineering, University of Florida , Gainesville, Florida 32608, USA.
authors.forename: Lorena
authors.initials: L
authors.lastname: Maldonado-Camargo
authors.affiliation: Department of Electrical and Computer Engineering, University of Florida , Gainesville, Florida 32608, USA.
authors.forename: David P
authors.identifier: 0000-0003-2515-7218
authors.initials: DP
authors.lastname: Arnold
authors.forename: Carlos
authors.initials: C
authors.lastname: Rinaldi