Formation of basal plane fiber‐textured Ti₂AlN films on amorphous substrates

Abstract

1 Introduction The M n+1 AX n phases (n = 1, 2 or 3, short MAX) are a class of ternary nanolaminates, consisting of a transition metal M, an A-group element A and either nitrogen and/or carbon as X. Due to alternating strong covalent M-X and weak metallic M-A bonds along the c-axis of their hexagonal lattice, they exhibit an unusual combination of metallic and high-performance ceramic properties, which has spawned a high scientific interest [1].Over the last years, MAX phases have also been investigated in thin film form, and their synthesis by various deposition techniques was demonstrated for several ternary carbides [2]. However for the nitrides, to date only Ti 2 AlN films were synthesized e.g. by reactive sputtering from elemental Ti and Al targets [2], where basal-plane oriented Ti 2 AlN(0001) films are usually achieved by epitaxial deposition onto lattice-matched MgO(111) or Al 2 O 3 (0001) substrates and require a minimum deposition temperature of 675 °C [2]. Depositions at lower temperatures induce a Ti 2 AlN growth with the c-axis tilted away from the substrate normal, accompanied by a polycrystalline film morphology and surface roughening [3]. Polycrystalline Ti 2 AlN does also form by solid-state reaction during annealing of AlN/Ti diffusion couples, with somewhat conflicting results depending on form of reactant, temperature and characterization

Fast pole figure acquisition using area detectors at the DiffAbs beamline – Synchrotron SOLEIL

“…The texture of a crystalline sample can be described as the preferred orientation of its crystallites (Cullity, 1978) and can vary from simple (e.g. random, fibrelike; Pellegrino et al, 2012;Remiens et al, 2011;Fei et al, 2009;Beckers et al, 2010;Deniz & Harper, 2008), to epitaxial (Remiens et al, 2011;Dong et al, 2001;Ö zcan et al, 2002;Barbier et al, 2007;Mocuta et al, 2003), to rather complex (e.g. axiotaxy; Detavernier et al, 2003;Detavernier & Lavoie, 2004).…”

Substrate orientation effects on the nucleation and growth of the Mn+1AXn phase Ti2AlC

“…If fiber texture nucleation on ͑111͒ TiC facets was possible, though, one might expect to see conventional nontilted fiber texture in MAX phase films grown on the TiC ͑111͒ surface, which has not been reported. Nontilted fiber textured MAX phase growth has been demonstrated recently, 23 but this required a specific processing sequence in which the Ti 2 AlC texture was inherited from the Ti layers of an annealed multilayer stack. The mechanism causing the tilted fiber texture we observe would seem to be an interesting topic for future work.…”