Superlattices and Microstructures 46 (2009) 95–100 Contents lists available at ScienceDirect Superlattices and Microstructures journal homepage: www.elsevier.com/locate/superlattices Ordered arrays of FePt nanoparticles on unoxidized silicon surface by wet chemistry A. Mari a,∗ , E. Agostinelli a , D. Fiorani a , A. Flamini a , S. Laureti a , D. Peddis a , A.M. Testa a , G. Varvaro a , M. Vasquez Mansilla a , A. Mezzi b , S. Kaciulis b a CNR – Istituto di Struttura della Materia, 00016 Monterotondo Scalo (RM), Italy b CNR – Istituto per lo Studio dei Materiali Nanostrutturati, 00016 Monterotondo Scalo (RM), Italy article info Article history: Available online 9 March 2009 Keywords: FePt nanoparticles Covalent anchoring Hydrogenated silicon Patterning XPS Magnetic properties abstract A new method, compatible with UV lithography patterning, for covalent anchoring of FePt nanoparticles from solution to unoxidized Si(100) surface has been set up. Continuous and patterned Fe 50 Pt 50 nanoparticle films have been prepared and their structural and magnetic properties have been investigated. © 2009 Elsevier Ltd. All rights reserved. 1. Introduction Ordered arrays of fct FePt nanoparticles are considered promising candidates for ultra-high density magnetic recording applications [1]. Therefore, controlled synthesis of these nanoparticles and their assembly on substrates suitable for technological applications have recently attracted great interest [2]. However, many relevant issues have still to be addressed, such as the robust (covalent) anchoring of the nanoparticles onto the substrate and the formation over an extended area of few layers of nanoparticles in dense regular arrays. In this context, it has been set up a procedure, compatible with UV lithography patterning, for covalent anchoring of FePt nanoparticles from solution to unoxidized Si(100) surface. Continuous and patterned Fe 50 Pt 50 nanoparticle films were obtained. The ordered particle assembly remained unchanged after the heat treatment up to 650 ◦ C, needed for fcc → fct phase conversion. Results of XPS and AFM investigations are presented and the magnetic properties of loose FePt nanoparticles (LNPs), FePt anchored on silicon, as prepared (ANPs) and after thermal treatment (TANPs), are compared and discussed. ∗ Corresponding author. Tel.: +33 90690672312. E-mail address: alessandra.mari@ism.cnr.it (A. Mari). 0749-6036/$ – see front matter © 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.spmi.2009.02.001