| 摘要 |
A transparent ceramic having as principal components terbium oxide (Tb 2 O 3 ) in a molar ratio of at least 40%; and at least one oxide selected among an yttrium oxide, a scandium oxide, and a lanthanide rare earth oxide, wherein (1) the crystal structure of the terbium-oxide-based ceramic does not contain a non-cubic-crystal phase, (2) the mean crystal particle diameter is in a range of 0.5 to 100 µm, and (3) the ceramic comprises a sintering auxiliary having no incidence of deposition of a non-cubic-crystal phase in the crystal structure of the terbium-oxide-based ceramic. This transparent ceramic makes it possible to provide a magneto-optical element that performs at least as well as terbium gallium garnet or other existing monocrystal materials. As regards optical loss and optical uniformity, it is possible to provide a functional element for an optical isolator in the infrared region between 500 nm and 1.5 µm having very little scattering and very few birefringence components. |
