TITLE:
Investigation of Some Structural and Mechanical Properties of Ba0.5CaxSr0.5-xTiO3 Ceramics
AUTHORS:
Lubna M. Sharaf El-Deen, Mohamed H. Badr, Abdel-Mageed H. Khafagy, Dalia U. Nassar
KEYWORDS:
BST Ceramics; BCST Ceramics; Phase Transition; Ultrasonic Attenuation; SEM
JOURNAL NAME:
Crystal Structure Theory and Applications,
Vol.2 No.3,
September
25,
2013
ABSTRACT: Ba0.5CaxSr0.5-xTiO3 (BCST) ceramics, where x = 0, 0.1, 0.2, 0.3 and 0.4, were prepared by
the conventional solid state reaction technique. X-ray diffraction (XRD)
analysis confirmed the formation of BST perovskite phase structure besides some
calcium oxide peaks for samples with high Ca content, x. Scanning electron
microscopy (SEM) results confirmed the XRD results, i.e., as x increased, the average grain size decreased. Energy
dispersive X-ray (EDX) analysis verified the increase of the amount of Ca
element with increasing of its content. Mechanical properties such as ultrasonic
attenuation, longitudinal wave velocity, and longitudinal elastic modulus were
studied by an ultrasonic pulse echo technique at 2 MHz frequency.
Investigations of ceramic microstructures and mechanical properties showed
their dependence on composition. Increasing of Ca content resulted in a
decrease in bulk density and ultrasonic attenuation and an increase in
porosity, velocity, and modulus. High temperature ultrasonic studies showed, in
addition to Curie phase transition, three or more relaxation peaks and its
origin was investigated.