Oxide dielectric and method for manufacturing same, and solid state electronic device and method for manufacturing same

A method for manufacturing an oxide dielectric, the method comprising:

• a heating step of heating, in an oxygen-containing atmosphere, a precursor derived from a precursor solution, as a starting material, comprising a bismuth (Bi)-containing precursor and a niobium (Nb)-containing precursor as solutes, to form an oxide (possibly including inevitable impurities) consisting essentially of bismuth (Bi), niobium (Nb), and oxygen, and to control contents of a first crystal phase of a pyrochlore-type crystal structure and a second crystal phase of a β-BiNbO4-type crystal structure, the oxide comprising:
• the first crystal phase of the pyrochlore-type crystal structure having a dielectric constant that decreases with increasing temperature of the oxide in a temperature range of 25° C. or more and 120° C. or less;
• and
• the second crystal phase of the β-BiNbO4-type crystal structure having a dielectric constant that increases with increasing temperature of the oxide in a temperature range of 25° C. or more and 120° C. or less.

A method for manufacturing an oxide dielectric, the method comprising:

• a heating step performed in such a manner that a content of a second crystal phase of a β-BiNbO4-type crystal structure is controlled to be 1.43 or more and 4.67 or less when a content of a first crystal phase of a pyrochlore-type crystal structure is assumed to be 1, by heating, in an oxygen-containing atmosphere, a precursor derived from a precursor solution, as a starting material, comprising a bismuth (Bi)-containing precursor and a niobium (Nb)-containing precursor as solutes, to form an oxide (possibly including inevitable impurities) consisting essentially of bismuth (Bi), niobium (Nb), and oxygen, the oxide comprising:
• the first crystal phase of the pyrochlore-type crystal structure;
• and
• the second crystal phase of the β-BiNbO4-type crystal structure.