The Key Role of Tin (Sn) in Microstructure and Mechanical Properties of Ti2SnC (M2AX) Thin Nanocrystalline Films and Powdered Polycrystalline Samples.

Snejana Bakardjieva,Štefan Michna,Jiří Plocek,Jaroslav Kupčík,Giovanni Ceccio,Bauyrzhan Ismagulov,Jiří Němeček,Vasily Lavrentiev,Jiří Vacík,Robert Klie

doi:10.3390/nano12030307

Abstract

Layered ternary Ti2SnC carbides have attracted significant attention because of their advantage as a M2AX phase to bridge the gap between properties of metals and ceramics. In this study, Ti2SnC materials were synthesized by two different methods—an unconventional low-energy ion facility (LEIF) based on Ar+ ion beam sputtering of the Ti, Sn, and C targets and sintering of a compressed mixture consisting of Ti, Sn, and C elemental powders up to 1250 °C. The Ti2SnC nanocrystalline thin films obtained by LEIF were irradiated by Ar+ ions with an energy of 30 keV to the fluence of 1.1015 cm−2 in order to examine their irradiation-induced resistivity. Quantitative structural analysis obtained by Cs-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) confirmed transition from ternary Ti2SnC to binary Ti0.98C carbide due to irradiation-induced β-Sn surface segregation. The nanoindentation of Ti2SnC thin nanocrystalline films and Ti2SnC polycrystalline powders shows that irradiation did not affect significantly their mechanical properties when concerning their hardness (H) and Young’s modulus (E). We highlighted the importance of the HAADF-STEM techniques to track atomic pathways clarifying the behavior of Sn atoms at the proximity of irradiation-induced nanoscale defects in Ti2SnC thin films.

Highlights

Introduction published maps and institutional affilThe MAX phases are a family of about 90+ carbides synthesized up to now with a basic stoichiometry nomenclature Mn+1 AXn, where M is an early transition d metal (i.e., Sc, Ti, V, Cr, Zr, Nb, Mo, Hf, and Ta), A represents an element from the IIIA or IVA groups of the periodic table (i.e., Al, Si, P, S, Ga, Ge, As, Cd, In, Sn, Tl, and Pb), and X is carbon or nitrogen
We provide an experiment in the understanding of Sn atoms surface segregation and highlight the importance of aberration-corrected
The Ti2 SnC M2 AX polycrystalline samples (PPS) were fabricated using a simplified method of sintering raw elemental powders

Summary

Introduction

The MAX phases are a family of about 90+ carbides (or nitrides) synthesized up to now with a basic stoichiometry nomenclature Mn+1 AXn , where M is an early transition d metal (i.e., Sc, Ti, V, Cr, Zr, Nb, Mo, Hf, and Ta), A represents an element (mainly) from the IIIA or IVA groups of the periodic table (i.e., Al, Si, P, S, Ga, Ge, As, Cd, In, Sn, Tl, and Pb), and X is carbon or nitrogen. The. MAX phases have a hexagonal crystal structure (a space group D4 6h , P63/mmc) with two units per cell. The idea of the ternary transition metal carbides referred to as the H phases, where H denotes hexagonal close-packed structures, was developed by Nowotny and Jeitschko almost 60 years ago [3]. The ternary transition metal carbides were classified as the Mn+1 iations

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