Ultrasonic characterization of co-additives effects on elastic moduli and acoustic properties of Li1-xCox Fe2O4

2^nd International Conference and Exhibition on Materials Science & Engineering

October 07-09, 2013 Hampton Inn Tropicana, Las Vegas, NV, USA

Ibrahim Hamid Qassem A-Suraihy, Abdellaziz Doghmane and Zahia Hadjoub

Accepted Abstracts: J Material Sci

Abstract :

Acoustic microscopes can be used to measure Rayleigh and longitudinal wave speeds in a specimen at microscopic resolution. The wave speeds are obtained from the interference pattern as a function of the defocus distance or V(z) curve. The received signal voltage amplitude V is generated by two beams, the normally reflected central beam and a nonspecularly reflected beam that strikes the fluid-solid interface at critical angle. In this context, we derive novel analytical expressions for co-additives effects on E, G, Poisson ratio, ν, longitudinal velocity, (VL) and transverse velocity, (VS). Such effects are also put into evidence for both reflectance functions, R(θ) and acoustic signatures, V(z). The elastic properties of lithium cobalt mixed ferrites of different compositions from the experimentally and simulation observed that the values of longitudinal (VL) wave velocities vary form 5140 m/s to 6841 m/s whereas transverse velocities (VS) from 3084 m/s to 4105 m/s. Moreover, Young?s (E) and bulk (n) moduli evaluated from the sound velocities as a function of cobalt doping and this moduli are increasing with increasing cobalt content. The Poisson?s ratio for all the samples was centered about a value of 0.2. The variation of the elastic moduli with composition was interpreted in terms of the binding forces between the atoms.

Biography :

Ibrahim Hamid Qassem AL-Suraihy is an Assistant Professor in Physics. He is working as Lecturer in the Faculty of Education, AL-Mahweet at Sana?a University. He has completed his Ph.D. at the age of 34 years from University of Badji Mokhtar Annaba, Algeria and master?s degree in University Stuttgart, Germany. He is the head of Department of Physics in the Faculty of Education, AL-Mahweet at Sana?a University. He has published more than 5 papers in reputed journals.