HIGH-TEMPERATURE SOUND-VELOCITY MEASUREMENT WITH PIEZOELECTRIC TRANSDUCERS

A technique for high temperature sound velocity measurement using piez oelectric transducers, that avoids the existence of the usual high tem perature bond between the sample and the buffer, was developed. This b ond is frequently responsible for a large attenuation and distortion o f the sound field, with a consequent inaccuracy in the experimental re sults. This technique was successfully used by the authors to make goo d quality measurements of sound velocity in iron-silicon single crysta ls from room temperature to T approximate to 1000 degrees C, unlike ot her authors who report strong attenuation in different regions of this temperature range for similar samples. The furnace, which is only 35 mm wide, allows work under magnetic held and a controlled atmosphere u p to 1300 degrees C. (C) 1998 American Institute of Physics.