Sputtering

We deposit X-ray molybdenum/silicon multilayer system, which can be used in the range from about 12 – 30 nm. Peak reflectance values are approaching 70% for normal incidence.

At very short X-ray wavelengths (wavelengths below about 4 nm) efficient normal incidence multilayers cannot be produced because interface roughness cause too much reduction in the reflectance. However periodic multilayers can still be used at near grazing incidence. They provide high reflectance at graze angles that are much larger than what can be achieved with single-layer coatings.

To evaluate the impact resistance of thin hard nanocomposite, multilayer and monolayer coatings in dynamic loading wear applications an impact test has been used. An impact testing of the coatings was proposed by Knotek et al in the 1990s. During testing the specimen is cyclically loaded by tungsten carbide ball that impacts of the coating/substrate surface. The test simulates a wide range of tribological systems.

Thin layers are prepared by magnetron sputtering by using the commercially available LEYBOLD-HERAEUS Z 550 sputtering device. This device enables one to produce smaller batches or single pieces with maximum diameter of 100 mm and thickness less then 20 mm. It is equipped with three magnetrons with targets of 152 mm in diameter (the typical target thickness is 6 mm) which enables the deposition of three different materials without interrupting the vacuum.