Langasite-type oxide material, method for producing same, and raw material used in the production method

A raw material, comprising a compound for producing a langasite oxide material, comprising:

• at least one element selected from the group consisting of Ir, Pr, Au, and Rh as an additive element;
• and
• at least one of a compound represented by formula:
• AE3TaGa3-XAlXSi2O14
• wherein AE represents an alkaline earth metal element selected from the group consisting of Mg, Ca, Sr, and Ba and 0≦X≦3, or a compound represented by formula:
• AE3NbGa3-XAlXSi2O14
• wherein AE represents an alkaline earth metal element selected from the group consisting of Mg, Ca, Sr, and Ba and 0≦X≦3.

A method for producing an oxide material, comprising:

• packing a raw material comprising a composition making up a composition of a desired solid oxide material in a crucible, thereby obtaining a packed raw material;
• melting the packed raw material, allowing a melt of the raw material to leak out through a hole provided in a die portion of the crucible, thereby spreading on the die portion;
• contacting a seed with the melt of the raw material leaked out on the die portion, thereby producing the oxide material from a contact portion;
• and
• moving the seed in a direction in which the seed is relatively pulled away from a die portion side of the crucible along a prescribed vertical axis, thereby producing the oxide material,
• wherein, at least sometime during the packing or the melting, the method further comprising:
• adding at least one element selected from the group consisting of Ir, Pt, Au, and Rh to the raw material as an additive element.