Structural, Corrosion And Mechanical Properties Of Sputtered Deposited Chromium Tungsten Nitride (Cr1-xWxN) Nanocomposite Thin Films

Adv. Mater. Lett., 2016, 7 (9), pp 723-729

DOI: 10.5185/amlett.2016.6362

Publication Date (Web): Jul 09, 2016

Copyright © IAAM-VBRI Press

E-mail: dkaurfph@iitr.ac.in

Abstract

Chromium tungsten nitride (Cr_1-xW_xN) thin films were successfully deposited on the silicon (100) substrate using dc magnetron reactive co-sputtering. The structural, surface morphological, electrochemical and mechanical properties were studied using X-ray diffraction, field emission-scanning electron microscopy, atomic force microscopy, electrochemical potentiostat and nanoindentation respectively. X-ray diffraction pattern with different atomic concentrations of tungsten (0<x<0.61) shows the presence of (111) and (200) orientation. The content of tungsten (W) in these thin films was controlled by varying the power on the W target. A small amount of tungsten addition led to the significant change in the structural, electrochemical and mechanical properties of the Cr_1-xW_xN films. The crystallite size varies from 31.1 nm to 15.2 nm with the W content due to variation in nucleation rate and reduction of the self-shadowing effect of the deposition process. Electrochemical properties of these thin films were studied by Tafel polarization curves, which explored the enhancement in corrosion rate due to the higher ratio of real surface area and projected area after a certain amount of W addition. Hardness follows the Hall-Petch relation and tends to increase with the decrease in grain size. Highest hardness 43.18 Gpa and elastic modulus 341.02 Gpa were achieved at the grain size of 15.2 nm in Cr_0.48W_0.43N thin film. 

Keywords

Magnetron, crystallite size, corrosion rate, nanoindentation, hardness.