Composition for forming ferroelectric thin film, and method for manufacturing same

A method for manufacturing a composition for forming a ferroelectric thin film, comprising:

• forming a precursor liquid of a ferroelectric thin film by putting raw materials of metal components of the ferroelectric thin film and a diol as a solvent into a reaction container and heating the raw materials and the solvent under reflux in an inert atmosphere;
• adding a reaction control substance to the precursor liquid, in such an amount that a Young's modulus of a film formed in a step of temporary firing at a temperature of 200° C. to 300° C. becomes equal to or less than 42 GPa, and a Young's modulus of a film formed in a step of permanent firing at a temperature of 400° C. to 500° C. becomes equal to or greater than 55 GPa;
• stirring and mixing the precursor liquid and the reaction control substance together;
• and
• adding the solvent thereto such that the concentration of a precursor of the ferroelectric thin film is adjusted to be 17% by mass to 35% by mass expressed in terms of an oxide.