A rare earth aluminate sintered compact including rare earth aluminate phosphor crystalline phases and voids, wherein an absolute maximum length of 90% or more by number of rare earth aluminate phosphor crystalline phases is in a range from 0.4 m to 1.3 m, and an absolute maximum length of 90% or more by number of voids is in a range from 0.1 m to 1.2 m.

A cutting tool (1) formed of a silicon nitride-based sintered body (2) including a matrix phase (3), a hard phase (4), and a grain boundary phase (10) in which a glass phase (11) and a crystal phase (12) exist. The sintered body (2) contains yttrium in an amount of 5.0 wt % to 15.0 wt % in terms of an oxide, and contains titanium nitride as the hard phase (4) in an amount of 5.0 wt % to 25.0 wt %. In an X-ray diffraction peak, a halo pattern appears at 2 ranging from 25 to 35 in an internal region of the sintered body (2). A ratio B/A of a maximum peak intensity B to a maximum peak intensity A satisfies 0.11B/A0.40 . . . Expression (1) in a surface region of the sintered body (2), and satisfies 0.00B/A0.10 . . . Expression (2) in the internal region of the sintered body (2).

A method of making a sintered ceramic body comprising the steps of disposing a ceramic powder (5) inside an inner volume of a spark plasma sintering tool (1), wherein the tool comprises: a die (2) comprising a sidewall comprising inner and outer walls, wherein the inner wall has a diameter defining the inner volume; upper and lower punches (4,4) operably coupled with the die, wherein each of the punches have an outer wall defining a diameter less than the diameter of the die inner wall, thereby creating a gap (3) between the punches and the inner wall when at least one of the punches are moved within the inner volume, and the gap is from 10 m to 70 m wide; creating vacuum conditions inside the inner volume; moving at least one of the punches to apply pressure to the ceramic powder while heating, and sintering; and lowering the temperature of the sintered body.

An antiballistic armor-plating component, includes a ceramic body made of a material comprising, as percentages by volume, between 35% and 55% of silicon carbide, between 20% and 50% of boron carbide, between 15% and 35% of a metallic silicon phase or of a metallic phase including silicon.

A multilayer coil component includes a multilayer body in which a plurality of insulating layers are stacked in a stacking direction and a coil inside, and outer electrodes on surfaces of the multilayer body and electrically connected to the coil. The insulating layers have a magnetic phase having spinel structure containing at least Fe, Ni, Zn, and Cu and a non-magnetic phase containing at least Si. When grain sizes D50 and D90 of crystal grains constituting the magnetic phase are respectively defined as equivalent-area circle diameters of 50% and 90% on a cumulative sum basis in a cumulative distribution of equivalent-area circle diameters of the crystal grains, the grain size D50 is from 50 nm to 750 nm, and the grain size D90 is from 200 nm to 1500 nm.

A method of making a sintered ceramic body comprising the steps of disposing a ceramic powder inside an inner volume of a spark plasma sintering tool, wherein the tool comprises: a die comprising a sidewall comprising inner and outer walls, wherein the inner wall has a diameter defining the inner volume; upper and lower punches operably coupled with the die, wherein each of the punches have an outer wall defining a diameter less than the diameter of the die inner wall, thereby creating a gap between the punches and the inner wall when at least one of the punches are moved within the inner volume, and the gap is from 10 m to 70 m wide; creating vacuum conditions inside the inner volume; moving at least one of the punches to apply pressure to the ceramic powder while heating, and sintering; and lowering the temperature of the sintered body.