Applied Surface Science 328 (2015) 170–176 Contents lists available at ScienceDirect Applied Surface Science journal h om epa ge: www.elsevier.com/locate/apsusc Micrometric rods grown by nanosecond pulsed laser deposition of boron carbide Ignacio Lopez-Quintas a , Mohamed Oujja a , Mikel Sanz a , Antonio Benitez-Ca ˜ nete a , Richard J. Chater b , Maria Vega Ca˜ namares c , José F. Marco a , Marta Castillejo a,∗ a Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain b Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom c Instituto de Estructura de la Materia, CSIC, Serrano 119, 28006 Madrid, Spain a r t i c l e i n f o Article history: Received 31 October 2014 Received in revised form 3 December 2014 Accepted 4 December 2014 Available online 12 December 2014 Keywords: Microrods Boron carbide Pulsed laser deposition a b s t r a c t Micrometric size rods have been fabricated via pulsed laser deposition in vacuum from boron carbide targets using nanosecond pulses of 1064 and 266 nm and room temperature Si (1 0 0) substrates. Mor- phological, structural and chemical characterization of the microrods was made by applying scanning electron microscopy, focussed ion beam microscopy coupled to secondary ion mass spectrometry, X- ray diffraction, X-ray photoelectron spectroscopy and micro-Raman spectroscopy. Ablation at 1064 nm favours the formation of microrods with high aspect ratio, sharp edges and pyramidal tips, typically 10 m long with a cross section of around 2 m × 2 m. Differently, at 266 nm the microrods are of smaller size and present a more globular aspect. The analyses of the microrods provide information about their crys- talline nature and composition, based on a mixture which includes boron, boron oxide and boron carbide, and allows discussion of the wavelength dependent growth mechanisms involved. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Nanomaterials display physical and chemical properties which strongly depend on their size and shape and therefore the ability to obtain diverse morphologies with controlled dimensions in the micro- and nanoscale is important for developing advanced functional materials [1]. Boron carbide (B 4 C) is a high hardness, lightweight, refractory compound, highly resistant to chemical agents, with extraordinary thermolectrical behaviour and high neutron absorption cross section. These exceptional properties are very much sought for the fabrication of coatings and cutting tools, in structural ceramics, thermoelectrical power generation, nuclear applications, and in other scientific and engineering areas [2–4]. The unique atomic structure of B 4 C consists of distorted B 11 C icosahedra, located at the corners of a unit cell of a rhombohedral lattice, connected along the (1 1 1) axis by atomic linear C B C chains [3,5]. Knowledge about the influence of microstructure and phase composition on the properties of boron carbide is impor- tant for the development of specific applications. To that ∗ Corresponding author. Tel.: +34 91 7459515. E-mail address: marta.castllejo@iqfr.csic.es (M. Castillejo). respect a number of works have focussed on the prepara- tion and investigation of pure and homogeneous boron carbide coatings with amorphous and polycrystalline structures using several fabrication techniques [4–6]. These include chemi- cal vapour deposition (CVD) [6,7], laser-assisted CVD [8,9], magnetron sputtering [10] and pulsed laser deposition (PLD) [11–16]. PLD studies of boron carbide have shown that morphology, stoi- chiometry and crystallinity of the deposits are very sensitive to variations of the laser parameters (pulse duration and energy and wavelength) and to deposition conditions, such as the atmosphere where ablation is carried out and the orientation, type and tem- perature of the substrate [11–15]. The in situ study of the B 4 C laser ablation plasma via optical emission spectroscopy and low-order harmonic generation has been proposed as a guide for controlled thin film synthesis through PLD [16–18]. Mostly amorphous B 4 C films have been grown by nanosecond UV laser ablation using the wavelengths of 266 and 248 nm [11,12,15]. Zemski et al. [14] have described boron carbide deposits with different morphologies by ablation with 532 nm, nanosecond laser pulses using Si (1 0 0) sub- strates placed at varying orientations with respect to the target. Ultrashort, femtosecond pulses have been applied for fabrication of boron carbide deposits with controlled morphology and stoichi- ometry [13]. http://dx.doi.org/10.1016/j.apsusc.2014.12.035 0169-4332/© 2014 Elsevier B.V. All rights reserved.