Thermal poling method, piezoelectric film and manufacturing method of same, thermal poling apparatus, and inspection method of piezoelectric property

Abstract

A thermal poling method in which a poling treatment can be performed easily by a dry process. The poling treatment is performed on a PZT film by performing a heat treatment on the PZT film under a pressurized oxygen atmosphere at a temperature of 400° C. or more and 900° C. or less. The PZT film before the heat treatment has a single-domain crystal structure, and the PZT film after the heat treatment has a multi-domain crystal structure.

1 . An inspection method of piezoelectric property, comprising the steps of: comparing peak positions in XRD results of each of a first ferroelectric film and a second ferroelectric film, determining that a piezoelectric property is excellent when the peak position of said second ferroelectric film is shifted to a lower-angle side than the peak position of said first ferroelectric film, and determining that a piezoelectric property is not excellent when the peak position of said second ferroelectric film is not shifted to a lower-angle side than the peak position of said first ferroelectric film, wherein
 said first ferroelectric film is one not subjected to a thermal poling treatment, and   said second ferroelectric film is one subjected to a thermal poling treatment.   
     
     
         2 . The inspection method of piezoelectric property according to  claim 1 , wherein
 said first ferroelectric film has a single-domain crystal structure, and   said second ferroelectric film has a multi-domain crystal structure.