Chimie Théorique Inorganique

Supervisory authorities

CNRS CNRS CNRS

Search





Home > In the headlines

Magnetic memory on nonmagnetic nanoparticles

published on

Magnetic memory on nonmagnetic nanoparticles


Publication:
Magnetic Memory from Site Isolated Dy(III) on Silica Materials
F. Allouche, G. Lapadula, G. Siddiqi, W. W. Lukens, O. Maury, B. Le Guennic, F. Pointillart, J. Dreiser, V. Mougel, O. Cador, C. Copéret
ACS Cent. Sci. 2017, DOI: 10.1021/acscentsci.7b00035


Abstract
Achieving magnetic remanence at single isolated metal sites dispersed at the surface of a solid matrix has been envisioned as a key step toward information storage and processing in the smallest unit of matter. Here, we show that isolated Dy(III) sites distributed at the surface of silica nanoparticles, prepared with a simple and scalable two-step process, show magnetic remanence and display a hysteresis loop open at liquid 4He temperature, in contrast to the molecular precursor which does not display any magnetic memory. This singular behavior is achieved through the controlled grafting of a tailored Dy(III) siloxide complex on partially dehydroxylated silica nanoparticles followed by thermal annealing. This approach allows control of the density and the structure of isolated, “bare” Dy(III) sites bound to the silica surface. During the process, all organic fragments are removed, leaving the surface as the sole ligand, promoting magnetic remanence.