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E. Aschauer, S. Sackl, T. Schachinger, T. Wojcik, H. Bolvardi, M. Arndt, P. Polcik, H. Riedl, P.H. Mayrhofer:
"Nano-structural investigation of Ti-Al-N/Mo-Si-B multilayer coatings: A comparative study by APT and HR-TEM";
Vacuum, 157 (2018), 173 - 179.

Nano-composites often represent a challenge for spatially resolved analysing methods. The overlap of specific
signals, for example in the mass-to-charge spectrum during atom probe tomography (APT) analysis or the intersection
of electron energy loss edges in electron energy loss spectroscopy (EELS), leads to highly challenging
results. Therefore, a complementary use of different techniques is essential to fully characterise a given system.
Within this work, we studied our Ti-Al-N/Mo-Si-B multilayer (comprising alternating 31 nm thin arc evaporated
fcc-Ti0.57Al0.43N layers and amorphous 6 nm thin Mo0.58Si0.28B0.14 layers), by high-resolution transmission
electron microscopy, EELS as well as APT and completed the results by comprehensive X-ray diffraction measurements.
We focused on the microstructure and crystallographic evolution during thermal loading - up to
1400 °C - and hence a detailed analytical description applying a wide set of high resolution techniques. When
exposed to high temperatures, the as-deposited amorphous MoSiB layers form the oxidation resistant, intermetallic
phases T1-Mo5Si3 and T2-Mo5SiB2. The layered arrangement between Ti-Al-N and Mo-Si-B allows to
postpone the formation of the comparative soft, hexagonal wurtzite type AlN (due to the decomposition of fcc-
Ti1-xAlxN layers) up to 1200 °C, which is by ∼200-300 °C above the typical formation temperature of w-AlN in
homogeneously grown single phase fcc-Ti1-xAlxN thin films.

http://dx.doi.org/10.1016/j.vacuum.2018.08.037

Project Head Paul Heinz Mayrhofer:
Christian Doppler Labors für anwendungsorientierte Schichtentwicklung