Hardness is an essential property for a wide range of applications. However, hardness alone, typically accompanied by brittleness, is not sufficient to prevent failure in ceramic films exposed to high stresses. Using VN as a model system, we demonstrate with experiment and density functional theory (DFT) that refractory VMoN alloys exhibit not only enhanced hardness, but dramatically increased ductility. V0.5Mo0.5N hardness is 25% higher than that of VN. In addition, while nanoindented VN, as well as TiN reference samples, suffer from severe cracking typical of brittle ceramics, V0.5Mo0.5N films do not crack. Instead, they exhibit material pile-up around nanoindents, characteristic of plastic flow in ductile materials. Moreover, the wear resistance of V0.5Mo0.5N is considerably higher than that of VN. DFT results show that tuning the occupancy of d–t2g metallic bonding states in VMoN facilitates dislocation glide, and hence enhances toughness, via the formation of stronger metal/metal bonds along the slip direction and weaker metal/N bonds across the slip plane

Thermoelectric properties of ScN thin films grown by reactive magnetron sputtering on Al2O3(0001) wafers are reported. X-ray diffraction and elastic recoil detection analyses show that the composition of the films is close to stoichiometry with trace amounts (similar to 1 at. % in total) of C, O, and F. We found that the ScN thin-film exhibits a rather low electrical resistivity of similar to 2.94 mu Omega m, while its Seebeck coefficient is approximately similar to-86 mu V/K at 800 K, yielding a power factor of similar to 2.5 x 10(-3) W/mK(2). This value is anomalously high for common transition-metal nitrides.Funding Agencies|Swedish Research Council (VR)|621-2009-5258

We review results on the growth of metastable Ti1-xAlxN alloy films by hybrid high-power pulsed and dc magnetron co-sputtering (HIPIMS/DCMS) using the time domain to apply substrate bias either in synchronous with the entire HIPIMS pulse or just the metal-rich portion of the pulse in mixed Ar/N2 discharges. Depending upon which elemental target, Ti or Al, is powered by HIPIMS, distinctly different film-growth kinetic pathways are observed due to charge and mass differences in the metal-ion fluxes incident at the growth surface. Al + ion irradiation during Al-HIPIMS/Ti-DCMS at 500 C, with a negative substrate bias Vs = 60 V synchronized to the HIPIMS pulse (thus suppressing Ar + ion irradiation due to DCMS), leads to single-phase NaCl-structure Ti1-xAlxN films (x ≤ 0.60) with high hardness (> 30 GPa with x > 0.55) and low stress (0.2-0.8 GPa compressive). Ar + ion bombardment can be further suppressed in favor of predominantly Al + ion irradiation by synchronizing the substrate bias to only the metal-ion-rich portion of the Al-HIPIMS pulse. In distinct contrast, Ti-HIPIMS/Al-DCMS Ti1-xAlxN layers grown with Ti + /Ti 2+ metal ion irradiation and the same HIPIMS-synchronized Vs value, are two-phase mixtures, NaCl-structure Ti1-xAlxN plus wurtzite AlN, exhibiting low hardness (≃18 GPa) with high compressive stresses, up to -3.5 GPa. In both cases, film

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The microstructure and composition of CrN x ( 1 0 x ) films grown by reactive High Power Pulsed Magnetron Sputtering (HIPIMS or HPPMS) have been studied as a function of the process parameters: N 2 -to-Ar discharge gas ratio, (f N2/Ar ), negative substrate bias (V s ), pulsing frequency, and energy per pulse. The film stoichiometry is found to be determined by the composition of the material flux incident upon the substrate during the active phase of the discharge with no nitrogen uptake between the high-power pulses. Scanning electron microscopy investigations reveal that for 0 < f N2/Ar < 0.15 and 150 V bias, a columnar film growth is

atmosphere. The fluorine content of the films was controlled by varying the CF 4 partial pressure from 0 mPa to 110 mPa at a constant deposition pressure of 400 mPa and a substrate temperature of 110 ºC. The films were characterized regarding their composition, chemical bonding and microstructure as well as mechanical properties by applying elastic recoil detection analysis, Xray photoelectron spectroscopy, Raman spectroscopy, transmission electron microscopy, and nanoindentation. First-principles calculations were carried out to predict and explain Fcontaining carbon thin film synthesis and properties. By geometry optimizations and cohesive energy calculations the relative stability of precursor species including C 2 , F 2 and radicals, resulting from dissociation of CF 4 , were established. Furthermore, structural defects, arising from the incorporation of F atoms in a graphene-like network, were evaluated. All as-deposited CF x films are amorphous. Results from X-ray photoelectron spectroscopy and Raman spectroscopy indicate a graphitic nature of CF x films with x ≤ 0.23 and a polymeric structure for films with x  0.26. Nanoindentation reveals hardnesses between ~1 GPa and ~16 GPa and an elastic recovery of up to 98 %.

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