Transparent Tetragonal Yttria‐Stabilized Zirconia Ceramics: Influence of Scattering Caused by Birefringence

Abstract

The correlation between grain size, optical birefringence, and transparency is discussed for tetragonal zirconia (ZrO 2 ) ceramics using the Mie, Rayleigh, and Rayleigh–Gans–Debye scattering models. Our results demonstrate that at the degree of mean birefringence in the range (0.03–0.04) expected for tetragonal ZrO 2 , only the Mie theory provides reasonable results. At small particle size (<50 nm) the more straightforward Rayleigh approximation correlates with the Mie model. A real in‐line transmission of ∼50% at visible light and 1 mm thickness is expected at a mean grain size <40 nm and ∼70% at a mean grain size <20 nm. At an infrared (IR) wavelength of 5 μm there should not be any scattering caused by birefringence for grain sizes <200 nm. Our simulations were validated with experimental data for tetragonal ZrO 2 (3 mol% Y 2 O 3 ) ceramics made from a powder with an initial particle size of ∼10 nm by sintering in air and using hot‐isostatic pressing. The maximum in‐line transmission of about 77% was observed at IR wavelengths of 3–5 μm.