| abstract |
A zirconia sol having zirconia crystals with an average primary particle size less than 20 nm is provided, wherein more than 90% of thezirconia crystals exist in the form of tetragonal and cubic crystal lattice structures. The zirconia sol has a transmittance more than 70% when the amount of the zirconia crystals in the zirconia sol is about 20 wt %. |