Unprecedented thermal stability of inherently metastable titanium aluminum nitride by point defect engineering

Extreme cooling rates during physical vapor deposition (PVD) allow growth of metastable phases. However, we propose that reactive PVD processes can be described by a gas–solid paraequilibrium defining chemical composition and thus point defect concentration. We show that this notion allows for point...

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Bibliographic Details
Main Authors: Moritz to Baben, Marcus Hans, Daniel Primetzhofer, Simon Evertz, Holger Ruess, Jochen M. Schneider
Format: Article
Language:English
Published: Taylor & Francis Group 2017-05-01
Series:Materials Research Letters
Subjects:
Online Access:http://dx.doi.org/10.1080/21663831.2016.1233914
Description
Summary:Extreme cooling rates during physical vapor deposition (PVD) allow growth of metastable phases. However, we propose that reactive PVD processes can be described by a gas–solid paraequilibrium defining chemical composition and thus point defect concentration. We show that this notion allows for point defect engineering by controlling deposition conditions. As example we demonstrate that thermal stability of metastable (Ti,Al)Nx, the industrial benchmark coating for wear protection, can be increased from 800°C to unprecedented 1200°C by minimizing the vacancy concentration. The thermodynamic approach formulated here opens a pathway for thermal stability engineering by point defects in reactively deposited thin films.
ISSN:2166-3831