Abstract: A ferrite sintered body includes a crystal grain of a Ni—Zn ferrite and a grain boundary thereof, in which Ti is unevenly distributed in an outer region of the crystal grain, the outer region extending from an interface of the crystal grain to a length of 20% of a major axis of the crystal grain.

Abstract: There are provided a light-emitting element mounting substrate which exhibits high reflectivity, and a light-emitting module having high reliability and high luminance. A light-emitting element mounting substrate includes an alumina sintered body containing alumina crystal, zirconia crystal, and grain boundary phase, wherein an intensity ratio It/Im between a peak intensity It of tetragonal zirconia crystal at 2? ranging from 30° to 30.5° and a peak intensity Im of monoclinic zirconia crystal at 2? ranging from 28° to 28.5° measured by X-ray diffractometer using Cu-K? radiation, is less than or equal to 35 excluding 0. Further, a light-emitting element module includes the light-emitting element mounting substrate, and a light-emitting element mounted thereon.

Abstract: [Object] To provide a ferrite sintered body and a ferrite core each of which has a high permeability, and a coil component produced by winding a metal wire around the ferrite core. [Solution] A ferrite sintered body includes a crystal grain of a Ni—Zn ferrite and a grain boundary thereof, in which Ti is unevenly distributed in an outer region of the crystal grain, the outer region extending from an interface of the crystal grain to a length of 20% of a major axis of the crystal grain. The ferrite sintered body contains Fe, Zn, Ni, Cu, and Ti. When the total of components of Fe, Zn, Ni, and Cu in terms of oxides thereof is assumed to be 100% by mole, a composition of the ferrite sintered body is 48% by mole or more and 50% by mole or less of Fe in terms of Fe2O3, 29% by mole or more and 31% by mole or less of Zn in terms of ZnO, 14% by mole or more and 16% by mole or less of Ni in terms of NiO, and 5% by mole or more and 7% by mole or less of Cu in terms of CuO. The ferrite sintered body contains 0.