Abstract: A cold storage material having a large thermal capacity in a ultra-low temperature range of 10 K or less and being highly durable against thermal shock and mechanical vibration. The cold storage material contains a rare earth oxysulfide ceramic represented by the general formula R2O2S in which R is one or more kinds of rare earth elements selected from La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y, and Al2O3 having a specific surface area of 0.3 m2/g to 11 m2/g is added to the cold storage material.

Abstract: Provided is a transparent rare earth aluminum garnet ceramic that has a highlight transmission rate and can be mass produced. The transparent rare earth aluminum garnet ceramic is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 71) and includes Si and Y as sintering aids, or is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 70) and includes Si and Lu as sintering aids.

Abstract: Provided is a cold storage material having a large thermal capacity in a ultra-low temperature range of 10 K or less and being highly durable against thermal shock and mechanical vibration. The cold storage material contains a rare earth oxysulfide ceramic represented by the general formula R2O2S (wherein R is one or more kinds of rare earth elements selected from La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y), and Al2O3 having a specific surface area of 0.3 m2/g to 11 m2/g is added to the cold storage material.

Abstract: Provided is a transparent rare earth aluminum garnet ceramic that has a highlight transmission rate and can be mass produced. The transparent rare earth aluminum garnet ceramic is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 71) and includes Si and Y as sintering aids, or is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 70) and includes Si and Lu as sintering aids.

Abstract: Provided is a transparent rare earth aluminum garnet ceramic that has a high light transmission rate and can be mass produced. The transparent rare earth aluminum garnet ceramic is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 71) and comprises Si and Y as sintering aids, or is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 70) and comprises Si and Lu as sintering aids.

Abstract: Provided is a transparent rare earth aluminum garnet ceramic that has a high light transmission rate and can be mass produced. The transparent rare earth aluminum garnet ceramic is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 71) and comprises Si and Y as sintering aids, or is represented by general formula R3Al5O12 (R is an element selected from the group consisting of rare earth elements having an atomic number of 65 to 70) and comprises Si and Lu as sintering aids.

Abstract: There is provided a rare-earth gallium garnet ceramic having a high extinction ratio and a high light transmittance. The rare-earth gallium garnet ceramic contains, as a sintering aid, 5 mass ppm or more and 500 mass ppm or less of Ge calculated as metal, and 20 mass ppm or more and 250 mass ppm or less of Al calculated as metal.

Abstract: There is provided a rare-earth gallium garnet ceramic having a high extinction ratio and a high light transmittance. The rare-earth gallium garnet ceramic contains, as a sintering aid, 5 mass ppm or more and 500 mass ppm or less of Ge calculated as metal, and 20 mass ppm or more and 250 mass ppm or less of Al calculated as metal.