XMCD Proof of Ferromagnetic Behavior in ZnO Nanoparticles

• Published in: Journal of physical chemistry. C Vol. 116; no. 11; pp. 6608 - 6614
• Main Authors: Guglieri, C, Laguna-Marco, M. A, García, M. A, Carmona, N, Céspedes, E, García-Hernández, M, Espinosa, A, Chaboy, J
• Format: Journal Article
• Language: English
• Published: Columbus, OH American Chemical Society 22-03-2012
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Magnetic properties of nanostructures; Physics; Amines; Thiols; Organic phosphine; Paramagnetism; Magnetic nanomaterial; Coatings; Nanoparticles; X-ray absorption spectra; Chemical bonds; Magnetic circular dichroism; Zinc oxide; Ferromagnetism; Organic compounds; Conformation
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp300837f

The combined element-specific X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) study of ZnO nanoparticles (NPs) capped with organic molecules confirms the occurrence of intrinsic ferromagnetic-like (FML) behavior up to room temperature (HTFM). Zn K-edge XMCD measurements reveal the coexistence of two different magnetic contributions: a paramagnetic response from the core of the NP, and a ferromagnetic-like contribution stemming from the interface formed between the ZnO core of the NP and the organic molecule. The extent and conformation of this interface depends on the capping molecule, and as demonstrated in ZnO/ZnS heterostructures, the FML behavior is reinforced when neat interfaces are formed.