PARAMAGNETIC GARNET-TYPE TRANSPARENT CERAMICS, MAGNETO-OPTIC MATERIAL AND MAGNETO-OPTIC DEVICE

To provide a LuTAG-based paramagnetic garnet-type transparent ceramic with a high laser damage threshold, a producing method thereof, a magneto-optic material, and a magneto-optic device.SOLUTION: A sintered body of a garnet-type composite oxide represented by following formula (1) is pressure sintered, and the pressure sintered body is heated to a temperature exceeding the processing temperature in the pressure sintering and re-sintered, and then the re-sintered body is subjected to oxidative annealing at a temperature above 1400°C under an oxidizing atmosphere. As a result, a paramagnetic garnet-type transparent ceramic having a lifetime of luminescence of 370 μs or more derived from the 5D4→7F5 transition of Tb(III) ions contained in the sintered body can be obtained. (Tb1-xLux)3Al5O12 (1) (In the formula,0.05≤x≤0.80) The magneto-optical device 100 is an optical isolator that can be used in a wavelength range of 0.9 μm or more and 1.1 μm or less comprising a Faraday rotator 110 made of the paramagnetic garnet-type transparent ceramic and polarizing materials 120 and 130.SELECTED DRAWING: Figure 1 【課題】ＬｕＴＡＧ系のレーザー損傷閾値の高い常磁性ガーネット型透明セラミックス、その製造方法、磁気光学材料及び磁気光学デバイスを提供する。【解決手段】下記式（１）で表されるガーネット型複合酸化物の焼結体を加圧焼結し、加圧焼結体を加圧焼結での処理温度を超える温度に加熱して再焼結し、再焼結体を１４００℃以上の酸化雰囲気で酸化アニール処理を行うことで、焼結体に含まれるＴｂ（ＩＩＩ）イオンの５Ｄ４→７Ｆ５遷移に由来する発光の寿命が３７０μｓ以上である常磁性ガーネット型透明セラミックスを得ることができる。（Ｔｂ１－ｘＬｕｘ）３Ａｌ５Ｏ１２（１）（式中、０．０５≦ｘ≦０．８０である。）磁気光学デバイス１００は、上記常磁性ガーネット型透明セラミックスからなるファラデー回転子１１０と、偏光材料１２０、１３０とを備えた波長帯０．９μｍ以上１．１μｍ以下で利用可能な光アイソレータである。【選択図】図１