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Thermal stability and mechanical properties of zirconium tungsten nitride (Zr–W–N) thin films have been studied. Nano-structured Zr–W–N thin films have been deposited on Si (100) substrates by reactive magnetron sputtering at varying substrate temperatures Ts (100°–600°C). For 100°C≤Ts ≤600°C, X-ray diffraction patterns of the films show a crystalline fcc phase with (111) and (200) preferred crystallographic orientations of grains. Maximum wear resistance (H/Er ~0.22) and maximum resistance to fatigue fracture (H3/Er 2 ~1.0GPa) have been obtained for the film deposited at Ts =400°C. Post annealing of the films deposited at 400°C has been carried out in air from 100°–600°C. Oxygen starts to be incorporated at 300°C and films begin to peel off above 400°C due to increase in oxygen incorporation. Hardness and elastic modulus of annealed films increase with increasing strain. [ABSTRACT FROM AUTHOR]

Thermal stability and mechanical properties of Zr–W–N films have been studied. Zr–W–N films of various structure have been deposited on Si substrates by DC/RF reactive magnetron sputtering at various substrate temperatures Ts (100°–600°C) and at constant N2 partial pressure (0.27Pa). For 100°C≤Ts ≤300°C, X-ray diffraction patterns show an amorphous structure of the films which is further confirmed by transmission electron microscopy measurements. For 400°C≤Ts ≤600°C, a crystalline fcc phase with (111) and (200) orientation has been observed. Maximum wear resistance (H/Er ~0.22) and maximum resistance to fatigue fracture (H3/Er 2 ~1.1GPa) have been obtained for the amorphous films deposited at Ts =200°C. Post annealing of films deposited at 200°C has been carried out in air from 100° to 600°C. Oxygen starts to be incorporated in the films at 300°C annealing temperature (Tn) and its content increases with increasing Tn. No crystalline oxide phases are observed up to Tn =600°C. The hardness of the annealed films decreases with increasing oxygen incorporation. [ABSTRACT FROM AUTHOR]

Abstract: The effect of nitrogen partial pressure (pN2) on structural, composition, deposition rate and mechanical properties of Zirconium Tungsten Nitride (ZrxW1−xNy) thin films have been studied. ZrxW1−xNy thin films have been deposited on silicon (100) substrates by DC/RF reactive magnetron sputtering. Structure and elemental composition of the deposited ZrxW1−xNy thin films strongly depend on pN2. XRD analysis shows that for 0.07Pa≤pN2 ≤0.17Pa, ZrxW1−xNy films exhibit single (fcc) phase, for 0.20Pa≤pN2 ≤0.27Pa, an amorphous phase is obtained and for 0.33Pa≤pN2 ≤0.67Pa reflections corresponding to dual (fcc+hcp) phase have been observed. The phase formation has been confirmed by TEM diffraction patterns. The root mean square roughness of the films varies non-monotonically with increasing pN2. The thickness of the films decreases continuously with increasing pN2. Results of nano-indentation analysis confirm moderate hardness, high wear resistance, high resistance to fatigue fracture and high adhesiveness of ZrxW1−xNy films. Among all the phases, maximum hardness (~24GPa) and maximum reduced elastic modulus (135GPa) have been obtained for dual phase (fcc+hcp) film while resistance to fatigue fracture (H3/Er 2 ~0.87GPa), wear resistance (H/Er ~0.2) and ductility for single phase (fcc) film were found to be maximum. No crack was observed to propagate in the films at a high load of 50mN. All the films were found to exhibit high adhesion with the substrate surface. [Copyright &y& Elsevier]

Abstract: The outdoor ceramic insulators of power transmission lines and transformers are suffering from the problem of contamination due to which surface flashover phenomenon is frequent. The main objective of this work was to prepare hydrophobic hafnium oxide (HfO2) thin films to mitigate contamination problem. The hafnium oxide coatings were deposited on glass substrates by DC reactive magnetron sputtering from a pure hafnium target. The depositions of HfO2 films were carried out in O2 +Ar and O2 +He atmosphere. The structural, optical and hydrophobic properties were examined by varying O2/Inert gas ratio. The prepared samples were characterized by X-ray diffraction, EDS, AFM, UV–vis-NIR spectrophotometer and contact angle goniometer. The coatings were found to be crystalline, transparent and hydrophobic for all samples. The deposition rate, hydrophobicity, transparency, band gap and particle size are better for the films deposited in argon atmosphere in comparison to helium. The hydrophobicity was found to be dependent on roughness of the film. The roughness (5.06nm) and the water contact angle (102.25°) were found maximum for the film deposited at O2/Ar ratio equals to 0.5. The transmittance was also found ~90% at this particular ratio. The band gap of the film deposited at above mentioned ratio was found to be 5.41eV ensuring insulating nature of the film. [Copyright &y& Elsevier]