D. J. Parekh, D. V. Barad, D. K. Thummar, N. S. Kanani, K. B. Modi
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引用次数: 0
Abstract
The structural, microstructural, optical, and elastic properties of polycrystalline perovskite series, Ca1+xCu3–xTi4O12; x = 0–1.0, have been investigated employing X-ray powder diffractometry, scanning electron microscopy, UV–Vis spectroscopy, and ultrasonic pulse-echo selection technique at 300 K. The primary structural parameter and ultrasonic parameters; longitudinal wave velocity (V1), the amplitude of transmitted and reflected pulses ao/an were used to calculate porous values of various elastic parameters such as shear wave velocities Vs, mean sound velocity Vm, elastic moduli L, B, G, E, Debye temperature θ, Poisson’s ratio σ, acoustic impedance Z, internal friction Q–1, absorptivity A, adiabatic compressibility Ba, Lame’s constant λL, and Vickers micro-hardness Hv. The elastic constants were emended to a void-free state using eight distinct semi-empirical methods. These models are principally relying on the pore morphology in the material. Depending upon the correction model employed, Lo is found to decrease from ~21.5 to ~39.5%, Bo from ~17.4 to 45.6%, while Eo and Go are found to decrease from ~22 to 34% on Ca2+ substitution (x = 0–0.5) in the system. Besides, the observed increase in different elastic moduli for x = 1.0 composition is found to vary from 0.3 to 7%. The compositional dependency of elastic moduli has been explained in terms of the change in interatomic bonding strength produced by variations in interatomic distances, microstructure, and electronic configuration. The values of Pough’s ratio Bo/Go, Frantsevich’s ratio Go/Bo, and Poisson’s ratio σo suggest the brittle nature of prepared ceramics.
期刊介绍:
Russian Journal of Nondestructive Testing, a translation of Defectoskopiya, is a publication of the Russian Academy of Sciences. This publication offers current Russian research on the theory and technology of nondestructive testing of materials and components. It describes laboratory and industrial investigations of devices and instrumentation and provides reviews of new equipment developed for series manufacture. Articles cover all physical methods of nondestructive testing, including magnetic and electrical; ultrasonic; X-ray and Y-ray; capillary; liquid (color luminescence), and radio (for materials of low conductivity).