AVS 53rd International Symposium
    Advanced Surface Engineering Thursday Sessions
       Session SE-ThA

Paper SE-ThA3
Characterisation of Nanocomposite Alumina-Zirconia Thin Solid Films Deposited by Reactive Dual RF Magnetron Sputtering

Thursday, November 16, 2006, 2:40 pm, Room 2007

Session: Hard and Nanocomposite Coatings: Synthesis, Structure, and Properties
Presenter: D.H. Trinh, Linköping University, Sweden
Authors: D.H. Trinh, Linköping University, Sweden
M. Collin, Sandvik Tooling AB, Sweden
I. Reineck, Sandvik Tooling AB, Sweden
S.S. Nonnenmann, Drexel University
J.E. Spanier, Drexel University
L. Hultman, Linköping University, Sweden
H. Högberg, Linköping University, Sweden
Correspondent: Click to Email
Alumina-zirconia composites are of interest for a wide range of applications. These include wear resistant coatings, requiring a combination of high hardness, thermal and chemical stability, and more advanced high-k dielectric thin films for microelectronics, which require the inherent insulating properties of both phases. A deeper understanding of the microstructure is required to fully harness the potential of the mixed oxide system and, in particular, nanocomposites within the aforementioned system. This is complicated, however, by the spontaneous phase separation process into binary oxides and the variety of possible stable and metastable phases that form within each respective binary system. In this study dual RF reactive magnetron sputtering has been utilised to deposit pure and mixed oxide films at a substrate temperature of 450°C on substrates such as Si (100) and WC-Co. High-resolution electron microscopy revealed that the films are nanocomposite in nature with grain sizes <50nm and that phase separation between alumina and zirconia occurs. The phase composition of the films was studied by x-ray diffraction. Complementary electron energy loss spectroscopy (EELS) and Raman scattering spectroscopy were performed for more in depth studies of the atomic arrangement and bonding. The pure zirconia films feature the monoclinic zirconia phase, while the pure alumina films consist of @gamma@-alumina phase. The composite films are nanocrystalline and are comprised of a mixture of phases that included the metastable zirconia phases, @gamma@-alumina, and some amorphous phase. The mechanical properties of the films were characterised by nanoindentation.