Design and validation of magnetic particle spectrometer for characterization of magnetic nanoparticle relaxation dynamics.
Design and validation of magnetic particle spectrometer for characterization of magnetic nanoparticle relaxation dynamics.
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DOI：
10.1063/1.4978003
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发表时间：
2017-05
期刊：
影响因子：
1.6
通讯作者：
Rinaldi C
中科院分区：
文献类型：
--
作者：
Garraud N;Dhavalikar R;Maldonado-Camargo L;Arnold DP;Rinaldi C
介绍了一种用于研究磁性纳米颗粒悬浮液线性和非线性行为的磁粒子谱仪（MPS）系统的设计和验证。MPS表征了由于弛豫和饱和效应引起的悬浮动态响应，这取决于磁性颗粒及其环境。该系统应用振幅和频率变化的正弦激励磁场，可配置为线性测量（1 mT，最高120 kHz）和非线性测量（50 mT，最高24 kHz）。以高达4 MS/s的速度进行时间分辨数据采集，结合基于硬件和软件的信号处理，可在非线性模式下进行高达50次谐波的宽带测量。通过用已知样品交叉校准仪器，可以定量地重建瞬时样品磁化强度。对氧化铁和钴铁氧体悬浮液进行两种MPS模式的验证，分别显示Néel和布朗松弛。
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.