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Yttralox

Yttralox is a transparent polycrystalline ceramic.

It was invented by Dr. Richard C. Anderson in 1965.

Yttralox has a cubic crystal structure and melts around 2400 degrees Centigrade.

It is prepared by mixing 90% Y2O3 with 10 % ThO2, cold pressing at or above 5000 psi, and firing in hydrogen for several minutes at about 2000 degree Centigrade.

The microstructure of pure Y2O3 without ThO2 is shown as having many pores and discontinuous grain growth at 100 power magnification. Under the same conditions Yttralox has no pores and shows uniform grain growth. (see picture)

Yttralox has high transmission uniformly from 0.25 microns in the ultraviolet to 9 microns in the infrared. (see picture). Its refractive index is 1.91 at room temperature.

It may be doped with 1 or 2 % of rare earth oxides, such as niobium, dysprosium, erbium, or iron oxide to give it a blue, green, yellow, or deep red color.

Yttralox may be used in air up to 1800 degree Centigrade without failure.

Yttralox is believed to be the world’s first transparent ceramic.