PROBLEM TO BE SOLVED: To provide a process for production of a composition for forming a lanthanum nickelate film capable to produce a composition for forming a lanthanum nickelate film without requiring a particular environment, in a short period of time and at low cost, a process for production of the lanthanum nickelate film, and a process for production of a piezoelectric element.

PROBLEM TO BE SOLVED: To provide a precursor solution of a piezoelectric film, which can make a film thickness of the piezoelectric film thick that is obtained in one film forming process, and has excellent storage stability.

PROBLEM TO BE SOLVED: To provide a method for producing a composition for forming a ceramic film capable of producing easily a composition for forming a ceramic film containing iron 2-ethylhexanoate without using a highly dangerous and noxious material, and to provide a piezoelectric ceramic film, and a method for producing iron 2-ethylhexanoate.

PROBLEM TO BE SOLVED: To provide a method for producing a composition for forming a ceramic film capable of producing easily a composition for forming a ceramic film containing bismuth 2-ethylhexanoate without using a highly dangerous and noxious material, and to provide a piezoelectric ceramic film, and a method for producing bismuth 2-ethylhexanoate.