| 摘要 |
PROBLEM TO BE SOLVED: To obtain a piezoelectric ceramic compsn. fit for electronic parts using a thickness-longitudinal vibration mode by using a pervoskite type compd. having a specified compsn. contg. Pb, Zr, Ti, Nb, Cr, Y and Co as metallic components. SOLUTION: This piezoelectric ceramic compsn. contains a perovskite type compd. contg. at least Pb, Zr, Ti, Nb, Cr, Y and Co as metallic components and represented by the formula (where M is Ca, Ba, La, Gd, Nd, Sm or Pr, 0.001<=x<=0.025, 0.95<=a<=1.05, 0.20<=b<=0.86, 0.04<=c<=0.43, 0.035<=d<=0.43, 0.06<=e<=0.18, 0.02<=f<=0.15, 0.47<=g<=0.53 and b+c+d=1.00). The compsn. has a high electromechanical coupling factor Kt, a low mechanical quality factor Qm and a low relative dielectric constant εr and can improve temp. characteristics of resonance frequency and reflowing characteristics. |
