Reversible post-synthesis tuning of the superparamagnetic blocking temperature of γ-Fe<inf>2</inf>O<inf>3</inf> nanoparticles by adsorption and desorption of Co(ii) ions

German Salazar-Alvarez, Jordi Sort, Abdusalam Uheida, Mamoun Muhammed, Santiago Suriñach, Maria Dolors Baró, Josep Nogués

Research output: Contribution to journalArticleResearchpeer-review

39 Citations (Scopus)

Abstract

The influence of the post-synthesis adsorption of Co(ii) ions on the structural and magnetic properties of maghemite (γ-Fe2O 3) nanoparticles with a mean particle size of about 10 nm has been investigated. It is shown that the step-wise adsorption of Co(ii) can controllably increase the blocking temperature, TB, of the system up to 60 K with respect to that of untreated particles, while neither the particle size nor the particle size distribution are significantly modified. This is accompanied by a four-fold increase in the coercivity, HC, at low temperatures. Using a selective leaching of the previously adsorbed Co(ii) ions the TB and HC values of the pristine γ-Fe 2O3 nanoparticles are recovered. Hence, a reversible and controllable tailoring of the magnetic properties (e.g., TB and HC) of the γ-Fe2O3 nanoparticles can be achieved by a simple adsorption and desorption process of Co(ii) ions after their synthesis. © The Royal Society of Chemistry.
Original languageEnglish
Pages (from-to)322-328
JournalJournal of Materials Chemistry
Volume17
DOIs
Publication statusPublished - 15 Jan 2007

Fingerprint

Dive into the research topics of 'Reversible post-synthesis tuning of the superparamagnetic blocking temperature of γ-Fe<inf>2</inf>O<inf>3</inf> nanoparticles by adsorption and desorption of Co(ii) ions'. Together they form a unique fingerprint.

Cite this