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Title: Characterization of the magnetic moment distribution in low-concentration solutions of iron oxide nanoparticles by a high-T{sub c} superconducting quantum interference device magnetometer

We developed a highly sensitive AC/DC magnetometer using a high-temperature superconductor superconducting quantum interference device for the evaluation of magnetic nanoparticles in solutions. Using the developed system, we investigated the distribution of magnetic moments of iron oxide multi-core particles of 100 nm at various iron concentrations that are lower than 96 μg/ml by analyzing the measured magnetization curves. Singular value decomposition and non-regularized non-negative least-squares methods were used during the reconstruction of the distribution. Similar distributions were obtained for all concentrations, and the iron concentration could be determined from the measured magnetization curves. The measured harmonics upon the excitation of AC and DC magnetic fields curves agreed well with the harmonics simulated based on the reconstructed magnetization curves, implying that the magnetization curves of magnetic nanoparticles were successfully obtained as we will show in the article. We compared the magnetization curves between multi-core particles of 100 nm and 130 nm, composed of 12-nm iron oxide nanoparticles. A distinctive magnetic property between the 100 nm and 130 nm particles in low-concentration solutions was successfully characterized. The distribution characteristic of magnetic moments suggests that the net magnetic moment in a multi-core particle is affected by the size of the magnetic cores and their degree of aggregation. Exploration ofmore » magnetic properties with high sensitivity can be expected using the developed system.« less
Authors:
; ; ;  [1] ; ;  [2]
  1. Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530 (Japan)
  2. Department of Electrical and Electronic Engineering, Kyushu University, Fukuoka 819-0395 (Japan)
Publication Date:
OSTI Identifier:
22409954
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COMPARATIVE EVALUATIONS; CONCENTRATION RATIO; EXCITATION; HIGH-TC SUPERCONDUCTORS; IRON; IRON OXIDES; LEAST SQUARE FIT; MAGNETIC CORES; MAGNETIC FIELDS; MAGNETIC MATERIALS; MAGNETIC MOMENTS; MAGNETIC PROPERTIES; MAGNETIZATION; MAGNETOMETERS; NANOPARTICLES; SQUID DEVICES