Variations in the saturation magnetization of nanosized NiFe2O4 particles on adsorption of carboxylic acids

• Main Authors: Ryo Kurosawa, Tsuneo Suzuki, Tadachika Nakayama, Hisayuki Suematsu, Koichi Niihara, Shigeo Satokawa, Yukiko Yasukawa, Xiaoxi Liu
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2014-03-01
• Series: Journal of Asian Ceramic Societies
• Subjects: NiFe2O4; Particles; Magnetic properties; Adsorption; Carboxylic acids
• Online Access: http://www.sciencedirect.com/science/article/pii/S2187076414000104

This work investigated magnetization changes in NiFe2O4 nanoparticles induced by the adsorption of a series of carboxylic acids. The application of formic acid resulted in a significant 8.6% decrease in the magnetization of NiFe2O4 nanoparticles at 18,000 Oe. With increasing carbon bond number in the saturated carboxylic acids, reductions in the magnetization of NiFe2O4 nanoparticles became around 4%. All unsaturated carboxylic acids produced approximately equivalent reductions in the magnetization, regardless of their double bond content. Based on these results, the observed NiFe2O4 magnetization changes appear to depend on either the polarity or the molecular size of the carboxylic acids and are believed to be caused by canting or pinning of spins in the vicinity of particle surfaces following adsorption of the acids.