Inter-university Research Institute Corporation National Institutes of Natural Sciences

Genesis Research Institute, Incorporated

Toyota Jidosha Kabushiki Kaisha

Jun Akiyama

Takunori Taira

Shigeo Asai

Kunihiko Hara

Upon producing a transparent polycrystalline material, a suspension liquid (or slurry) is prepared, the suspension liquid being made by dispersing a raw-material powder in a solution, the raw-material powder including optically anisotropic single-crystalline particles to which a rare-earth element is added. A formed body is obtained from the suspension liquid by means of carrying out slip casting in a space with a magnetic field applied. On this occasion, while doing a temperature control so that the single-crystalline particles demonstrate predetermined magnetic anisotropy, one of static magnetic fields and rotary magnetic fields is selected in compliance with a direction of an axis of easy magnetization in the single-crystalline particles, and is then applied to them. A transparent polycrystalline material is obtained by sintering the formed body, the transparent polycrystalline material having a polycrystalline structure whose crystal orientation is controlled.

Transparent polycrystalline material and production process for the same

Provided is a method for manufacturing a translucent polycrystalline material with optical properties continuously varying in the material. A slurry including single crystal grains that are acted upon by a force when placed in a magnetic field is immobilized in a gradient magnetic field with a spatially varying magnetic flux density and then sintered. For example, where a slurry including single crystal grains of YAG doped with Er and single crystal grains of YAG undoped with a rare earth material is immobilized in the gradient magnetic field, the region with a strong magnetic field becomes a laser oscillation region that is rich in Er-doped YAG, whereas the region with a weak magnetic field becomes a translucent region rich in YAG undoped with a rare earth material. A polycrystalline material having a core with laser oscillations and a guide surrounding the core are obtained at once.

Translucent polycrystalline material and manufacturing method thereof

Upon producing a transparent polycrystalline material, a suspension liquid (or slurry) is prepared, the suspension liquid being made by dispersing a raw-material powder in a solution, the raw-material powder including optically anisotropic single-crystalline particles to which a rare-earth element is added. A formed body is obtained from the suspension liquid by means of carrying out slip casting in a space with a magnetic field applied. On this occasion, while doing a temperature control so that the single-crystalline particles demonstrate predetermined magnetic anisotropy, one of static magnetic fields and rotary magnetic fields is selected in compliance with a direction of an axis of easy magnetization in the single-crystalline particles, and is then applied to them. A transparent polycrystalline material is obtained by sintering the formed body, the transparent polycrystalline material having a polycrystalline structure whose crystal orientation is controlled. In this calcination step, after subjecting the formed body to primary sintering at a temperature of 1,600-1,900 K, the resulting primarily-sintered body undergoes hot-isotropic-press sintering (or HIP processing) at a temperature of 1,600-1,900 K.

Growing community of inventors

Okazaki, Japan

Jun Akiyama