Sm-Substituted Lead Titanate Ceramics for High Frequency Ultrasonic Probes

Abstract

Modified lead titanate ceramics with exceptionally large electromechanical anisotropy (ratio of electromechanical coupling factor for thickness vibration to that for planar vibration is more than 15) are produced. These ceramics have a chemical formula (Pb 1-(3 x /2) Sm x ) (Ti 1- y Mn y )O 3 . They are found to be very useful in ultrasonic probe applications due to their extremely small coupling factor of unwanted lateral vibration ( k 31 , k p ). High frequency (7.5∼15 MHz) ultrasonic probes using these ceramics are developed for medical use.