Patent ID: 8322828

Claim:
A liquid jet head comprising: a nozzle plate having a nozzle opening; a pressure chamber substrate having a pressure chamber communicating with the nozzle opening and formed above the nozzle plate; a vibration plate formed on one side of the pressure chamber substrate; and a piezoelectric element formed above the vibration plate and provided at a position corresponding to the pressure chamber, wherein the piezoelectric element includes two electrodes, a piezoelectric layer provided between the electrodes, and an orientation layer that is provided between one of the electrodes closer to the vibration plate and the piezoelectric layer, wherein the orientation layer includes a mixed crystal comprising LaNiO 2 , LaNiO 3 , La 2 NiO 4 and La 3 Ni 2 O 7 , or a mixed crystal comprising LaNiO 2 , LaNiO 3 and La 2 NiO 4 .