Suchergebnisse

In this work, amorphous thin films in Mg-Si-O-N system typically containing amp;gt; 15 at.% Mg and 35 at.% N were prepared in order to investigate especially the dependence of optical and mechanical properties on Mg composition. Reactive RF magnetron co-sputtering from magnesium and silicon targets were used for the deposition of Mg-Si-O-N thin films. Films were deposited on float glass, silica wafers and sapphire substrates in an Ar, N-2 and O-2 gas mixture. X-ray photoelectron spectroscopy, atomic force microscopy, scanning electron microscopy, spectroscopic ellipsometry, and nanoindentation were employed to characterize the composition, surface morphology, and properties of the films. The films consist of N and Mg contents up to 40 at.% and 28 at.%, respectively and have good adhesion to substrates and are chemically inert. The thickness and roughness of the films increased with increasing content of Mg. Both hardness (16-21 GPa) and reduced elastic modulus (120-176 GPa) are strongly correlated with the amount of Mg content. The refractive index up to 2.01 and extinction coefficient up to 0.18 were found to increase with Mg content. The optical band gap (3.1-4.3) decreases with increasing the Mg content. Thin film deposited at substrate temperature of 100 degrees C shows a lower value of hardness (10 GPa), refractive index (1.75), and higher values of reduced elastic modulus (124 GPa) as compared to the thin film deposited at 310 degrees C and 510 degrees C respectively, under identical synthesis parameters. ; Funding Agencies|VINNOVA [2015-04809]; AForsk Foundation [14-457]; European Research Council under the European Community/ERC [335383]; Swedish Foundation for Strategic Research (SSF); Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]

Cr2N is commonly found as a minority phase or inclusion in stainless steel, CrN-based hard coatings, etc. However, studies on phase-pure material for characterization of fundamental properties are limited. Here, Cr2N thin films were deposited by reactive magnetron sputtering onto (0001) sapphire substrates. X-ray diffraction and pole figure texture analysis show Cr2N (0001) epitaxial growth. Scanning electron microscopy imaging shows a smooth surface, while transmission electron microscopy and X-ray reflectivity show a uniform and dense film with a density of 6.6gcm(-3), which is comparable to theoretical bulk values. Annealing the films in air at 400 degrees C for 96h shows little signs of oxidation. Nano-indentation shows an elastic-plastic behavior with H=18.9GPa and E-r=265GPa. The moderate thermal conductivity is 12Wm(-1)K(-1), and the electrical resistivity is 70cm. This combination of properties means that Cr2N may be of interest in applications such as protective coatings, diffusion barriers, capping layers and contact materials. ; Funding Agencies|European Research Council under the European Communitys Seventh Framework Programme (FP/2007-2013)/ERC Grant [335383]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [200900971]; Swedish Foundation for Strategic Research (SSF) through the Future Research Leaders 5 program; Knut and Alice Wallenberg foundation through the Wallenberg Academy Fellows program; Swedish Research Council (VR) [2016-03365]; Aforsk Foundation [16-359]; Carl Tryggers Foundation [CTS 17:166]

CrN thin films with an N/Cr ratio of 95% were deposited by reactive magnetron sputtering onto (0001) sapphire substrates. X-ray diffraction and pole figure texture analysis show CrN (111) epitaxial growth in a twin domain fashion. By changing the nitrogen versus argon gas flow mixture and the deposition temperature, thin films with different surface morphologies ranging from grainy rough textures to flat and smooth films were prepared. These parameters can also affect the CrN(x )system, with the film compound changing between semiconducting CrN and metallic Cr2N through the regulation of the nitrogen content of the gas flow and the deposition temperature at a constant deposition pressure. Thermoelectric measurements (electrical resistivity and Seebeck coefficient), scanning electron microscopy, and transmission electron microscopy imaging confirm the changing electrical resistivity between 0.75 and 300 m omega cm, the changing Seebeck coefficient values between 140 and 230 mu VK-1, and the differences in surface morphology and microstructure as higher temperatures result in lower electrical resistivity while gas flow mixtures with higher nitrogen content result in single phase cubic CrN. ; Funding Agencies|European Research Council under the European Community/ERC [335383]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]; Swedish Foundation for Strategic Research (SSF) through the Future Research Leaders 5 program; Knut and Alice Wallenberg Foundation under the Wallenberg Academy Fellows program; Swedish Research Council (VR) [2016-03365]; European Union; Danish Innovation Fund for the NanoCaTe project [604647]; Danish Innovation Fund for the CTEC project [1305-00002B]