SQUID magnetometry combined with in situ cyclic voltammetry: A case study of tunable magnetism of [Formula: see text]-Fe2O3 nanoparticles

J Magn Magn Mater. 2013 Mar;329(2-2):43-48. doi: 10.1016/j.jmmm.2012.09.071.

Abstract

SQUID magnetometry combined with in situ cyclic voltammetry by means of a three-electrode chemical cell opens up novel potentials for studying correlations between electrochemical processes and magnetic behaviour. The combination of these methods shows that the charge-induced variation of the magnetic moment of nanocrystalline maghemite ([Formula: see text]-Fe2O3) of about 4% strongly depends on the voltage regime of charging. Upon positive charging, the charge-induced variation of the magnetic moment is suppressed due to adsorption layers. The pronounced charge-sensitivity of the magnetic moment in the regime of negative charging may either be associated with a redox reaction or with charge-induced variations of the magnetic anisotropy or magnetoelastic coupling.

Keywords: Charge-induced magnetism variation; In situ electrochemistry; Multifunctional property; Nanocrystalline material; SQUID magnetometry.