Abstract: A hydride ion conductor represented by a general formula: Ba2-x-mAxMg1-y-nByH6-x-y-2m-2n??(1), wherein A and B are each selected from at least one or more of the group consisting of Li, Na, K, Rb, and Cs, and 0?x?1, 0?y?1, 0?m?0.2, and 0?n?0.2, excluding a case where x=y=m=n=0.

Abstract: A hydride ion conductor is represented by: MAMBH4-xFx??Formula (1), where MA is selected from the group consisting of Ca, Sr, and Ba, MB is selected from the group consisting of Mg and Ca, and is different from MA, and x is 0<x<4.

Abstract: A glass frit includes a glass which contains: Li; at least one selected from the group consisting of B, Si, P, Ge, and Te; O; and at least one selected from the group consisting of F, Cl, Br, and I. The glass is to turn into a crystallized glass including an amorphous phase and a crystalline phase, the crystalline phase precipitated by a heat treatment at a temperature equal to or higher than a glass transition temperature and equal to or lower than a glass crystallization temperature. The crystallized glass shows diffraction peaks at 2?=22.8±0.5°, 2?=32.1±0.5° and 2?=39.6±0.5° in a powder X-ray diffraction pattern using Cu—K? radiation.