Patent ID: 7511409

Claim:
An electron emitter comprising a substrate; an emitter section formed of a dielectric material and bonded onto a surface of the substrate; and a first electrode provided on a top surface of the emitter section and a second electrode provided on a bottom surface of the emitter section, such that the second electrode is bonded onto the surface of the substrate and the emitter section is bonded onto the second electrode; wherein the dielectric material forming the emitter section has an electric-field-induced strain of 0.07% or less, the electric-field-induced strain being percent deformation under application of an electric field of 4 kV/mm, as measured in a direction perpendicular to the electric field; wherein the dielectric material comprises a dielectric composition which contains, as a primary component, a composition represented by the following formula (1): Pb x Bi p (Mg y/3 Nb 2/3 ) a Ti b-z M z Zr c O 3 (1) wherein x, p, and y satisfy the following relations: 0.85â‰¦xâ‰¦1.03, 0.02â‰¦pâ‰¦0.1, and 0.8â‰¦yâ‰¦1.0; a, b, and c are decimal numbers falling within a region formed by connecting the following five points (0.550, 0.425, 0.025), (0.550, 0.150, 0.300), (0.100, 0.150, 0.750), (0.100, 0.525, 0.375), and (0.375, 0.425, 0.200) in a triangular coordinate system of (a, b, c) having the following three vertexes (1, 0, 0), (0, 1, 0), and (0, 0, 1); z satisfies the following relation: 0.02â‰¦zâ‰¦0.10; M is at least one element selected from among Nb, Ta, Mo, and W; and wherein the dielectric composition contains Ni in an amount of 0.05 to 2.0 wt% as reduced to NiO and Mn in an amount of 0.05 to 1.0 wt% as reduced to MnO 2 ; and wherein the thermal expansion coefficient of the substrate is greater than that of the emitter section.