Wüest M. 51 Wykes M. 82 Yamaguchi M. 17 Ybarra G. 129 Yubero F ...

JUNE 28 WEDNESDAY AFTERNOON
JS2-WeA-P.6 OPTICAL AND STRUCTURAL STUDY OF EB-PVD ZrO 2 THIN FILMS.I.
M. Ochando, M. Vila and C. Prieto. Instituto de Ciencia de Materiales de Madrid, Consejo Superior
de Investigaciones Científicas. Cantoblanco, 28049 – MADRID, Spain.
Zirconium oxide is a widely used material because of its heat resistance, low thermal conductivity,
high refractive index and high transparency in the visible and near infrared region, very high chemical
inertness and high laser damage threshold. Due to these properties, its applications can be found in
very different aspects of technology. For instance, zirconia has been applied as thermal barrier coating
(1), optical filters, laser mirrors(2), buffer layer for high T C superconductor on Si (3), high temperature
oxygen separation (4), oxygen sensors(5), and solid oxide fuel cells(6).
Films of zirconia can be prepared by different techniques. Typically, thin films prepared by sputtering
are used for gate dielectric in microelectronics applications and zirconia films prepared by electron
beam physical vapour deposition (EB-PVD) are candidates for advanced thermal barrier coatings
(TBC) for the new generation of land-based gas turbines as well as for optical applications. In the interest
host materials with a high luminescent efficiency and superior stabilization, tetragonal ZrO2 is
an attractive material due to the refractive index, electrical, chemical and mechanical characteristics.
ZrO 2 thin films prepared on Si(100) substrates by electron beam physical vapour deposition (EB-
PVD) are investigated by X-ray diffraction and optical absorption spectroscopy. Results show tetragonal
stabilized phases of zirconium oxide independently of the yttria addition in the starting material. In
this work, it is reported the variation of the crystallite size as a function of the deposition rate, showing
that crystallites are in the nanometric range and that a remarkable crystallite size increase is observable
for thin films prepared at low deposition rates.
In addition, it is presented the optical absorption spectroscopy characterization in order to determine
the refractive index; the obtained values does not depend on the deposition rate being in agreement
with the bulk ones. It is shown EB-PVD prepared samples have good performance for optical and protective
coatings.
2
3
4
5
6
S.M. Meier, D.K. Gupta, J Eng. Gas Turbines Power Trans. ASME 116 (1994) 250.
W.H. Lowdermilk, D. Milam, F. Rainer, Thin Solid Films 73 (1980) 155.
D.K. Fork, D.B. Fenner, G.A.N. Connell, J.M. Phillips, T.H. Geballe, Appl. Phys. Lett. 57 (1990) 1137.
J. Han, Y.Zeng, G. Xomeritakis, Y.S. Lin, Solid State Ionics 98 (1997) 63.
M. Sayer , K.Sreenivas, Science 247 (1990) 1056.
N.Q. Minh, J. Am. Ceram. Soc. 76 (1993) 563.
138