Abstract: Provided is an yttrium ingot from which an yttrium sputtering target that produces a reduced number of particles can be obtained, and an yttrium sputtering target that has high plasma resistance and a low resistance that enables realization of a high film deposition rate can be obtained. An yttrium ingot, wherein the yttrium ingot has a fluorine atom content of less than or equal to 10 wt %; in an instance where the yttrium ingot constitutes a target, a sputtering surface of the target has a surface roughness of 10 nm or greater and 2 ?m or less; in the yttrium ingot, the number of pores having a diameter of greater than or equal to 100 ?m is fewer than or equal to 0.1/cm2; and the yttrium ingot has a relative density of greater than or equal to 96%.

Abstract: An oxide sintered body containing indium, hafnium, tantalum, and oxygen as constituent elements, in which when indium, hafnium, and tantalum are designated as In, Hf, and Ta, respectively, the atomic ratio of Hf/(In+Hf+Ta) is equal to 0.002 to 0.030, and the atomic ratio of Ta/(In+Hf+Ta) is equal to 0.0002 to 0.013.

Abstract: The object of the present invention is to provide a large-sized gallium nitride-based sintered body having a small oxygen amount and high strength, a large-sized gallium nitride-based sintered body having a small oxygen amount and containing a dopant, to obtain a highly crystalline gallium nitride thin film which has become a n-type or p-type semiconductor by a dopant, and methods for producing them. A gallium nitride-based sintered body, which has an oxygen content of at most 1 atm % and an average particle size (D50) of at least 1 ?m and at most 150 ?m.

Abstract: An oxide sintered body containing indium, hafnium, tantalum, and oxygen as constituent elements, in which when indium, hafnium, and tantalum are designated as In, Hf, and Ta, respectively, the atomic ratio of Hf/(In+Hf+Ta) is equal to 0.002 to 0.030, and the atomic ratio of Ta/(In+Hf+Ta) is equal to 0.0002 to 0.013.

Abstract: An oxide sintered body containing indium, hafnium, tantalum, and oxygen as constituent elements, in which when indium, hafnium, and tantalum are designated as In, Hf, and Ta, respectively, the atomic ratio of Hf/(In+Hf+Ta) is equal to 0.002 to 0.030, and the atomic ratio of Ta/(In+Hf+Ta) is equal to 0.0002 to 0.013.

Abstract: Provided are an oxide sintered body that can produce a transparent conductive oxide film having low resistance and exhibiting lower light absorption characteristics in a wide wavelength range, and a transparent conductive oxide film. An oxide sintered body containing indium, hafnium, tantalum, and oxygen as constituent elements, in which when indium, hafnium, and tantalum are designated as In, Hf, and Ta, respectively, the atomic ratio Hf/(In+Hf+Ta) is 0.2 at % to 3.0 at %, and the atomic ratio Ta/(In+Hf+Ta) is 0.02 at % to 1.3 at %, is used.