A high-temperature oxidation-resistant diffusion barrier for PbZrxTi1-xO3 coating on nanocrystalline diamond film

Abstract

A buffer layer for PbZrxTi1-xO3 (PZT) coating on nanocrystalline diamond (NCD) film was investigated to prevent the oxidation damage of NCD layer during ambient air annealing at high-temperature. As for the phase of buffer layer, metal nitride is more effective than pure metal for enhancing adhesion of PZT coating on NCD film. For the metal nitride-based buffer layer, the incorporation of Al and Si increases further the adhesive strength of Pit coating on NCD film. As a microstructural point of view, nanoscale multilayered structure was observed to contribute to the increase of adhesive strength between PZT and NCD. As a consequence, introducing thin (similar to 70 nm) composite buffer composed of Ti(Al)N/SiNx nanoscale multilayer with bilayer period of similar to 5 nm as an intermediate layer between PZT coating and NCD film improved the high-temperature oxidation resistance of the NCD film and relevant adhesive strength of PZT coating even after the 900 degrees C air-annealing. The improved adhesion was attributed to the suppressed oxygen diffusion to the NCD film through the PZT layer at high temperature by the intervening nanoscale multilayer buffer. (C) 2014 Elsevier B.V. All rights reserved.