Electrical and Frequency Characteristics of Third-Overtone Vibration-Mode Surface Mount Device High-Frequency Filter Using Modified PbTiO₃Ceramics

Novel 0.50(Bi1-xLax)FeO3–0.35PbTiO3–0.15Bi(Zn1/2Ti1/2)O3Piezoelectric Ceramics for High Temperature High Frequency Filters

“…PZT piezoceramics usually exhibit a relatively low Curie temperature T C below 386 C and PT such as Matsushita lead titanate (MLT) ceramics has a T C ¼ 495 C, which is the only known perovskite-structured piezoceramics practically available for application in the fields of high temperature filters. [1][2][3][4][5][6] Moreover, to make ceramic resonators and filters higher than 10 MHz, PT is also better than PZT because of larger mechanical quality factor Qm and smaller dielectric constant. [2][3][4][5][6] For increasing high temperature applications including filters and sensors, novel perovskite-structured ferroelectric piezoceramics have been intensively and widely investigated these years.…”

“…[1][2][3][4][5][6] Moreover, to make ceramic resonators and filters higher than 10 MHz, PT is also better than PZT because of larger mechanical quality factor Qm and smaller dielectric constant. [2][3][4][5][6] For increasing high temperature applications including filters and sensors, novel perovskite-structured ferroelectric piezoceramics have been intensively and widely investigated these years. Till now, BiMeO 3 -PbTiO 3 (Me is a single ion of valence 3+ (e.g., Sc or Fe) or a mixture with an average valence 3+ (e.g., Mg 1=2 Ti 1=2 or Zn 1=2 Ti 1=2 ) solid solutions have been evidenced to have T C above 450 C. Nevertheless, owing to either the absence of morphotropic phase boundary (MPB) or high conductivity, poor performances limit their experimental characterizations and practical applications at present.…”