Piezoelectric/electrostrictive element having electrode film(s) with specified surface roughness

摘要

A piezoelectric/electrostrictive element is disclosed which includes at least one piezoelectric/electrostrictive portion each of which consists of a lower electrode film, a piezoelectric/electrostrictive film and an upper electrode film. In this element, at least the lower one of the electrode films has a surface roughness represented by maximum peak-to-valley roughness height Rmax. or Ry which is in a range of 3 mu m DIFFERENCE 14 mu m, and a surface roughness represented by centerline mean roughness Ra which is not larger than 2 mu m.