Abstract

Inhomogeneity and a lack of reproducibility in optical thin film coatings has been attributed in part to chemical decomposition and phase transitions which may occur during exposure to the high temperatures frequently present during deposition. A stable material which does not exhibit phase transitions or decomposition could significantly improve the reproducibility of thin film fabrication. Potentially large groups of materials which fit these requirements exist as ceramics and as solid solutions formed from combinations of many common refractory oxide materials. The combination of ZrO₂, HfO₂ and Y₂O₃ has been shown to form a solid solution with a stable crystalline phase at high temperatures.¹ In the present investigation, we have studied the properties of optical thin films deposited from solid solutions of these materials of varying compositions. Analysis of these coatings indicates that generally improved optical films can be obtained using solid solution mixtures in comparison to films deposited from single component starting materials.

© 1988 Optical Society of America