Journal of Pure and Applied Ultrasonics

Jitendra Kumar ¹, S. K. Shrivastava ², Kailash ³

Affiliations
1 Department of Physics, Rajkiya Mahila Snatakottar Mahavidhyalaya, Banda-210001, IN
2 Department of Physics, Bundelkhand University, Jhansi-284001, IN
3 Department of Physics, B.N. P.G. College, Rath, Hamirpur-210431, IN

Abstract

The calcium oxide crystal possesses well developed fcc structure and is divalent in nature. Oxides and silicates make up the bulk of the Earth's mantle and crust, and thus it is important to predict their behavior for the study of seismic and volcanic activities. The second order elastic constants (SOECs) were computed using Coulomb and Born-Mayer potential in the temperature range 100-1000 K. The ultrasonic velocities were calculated using these values of second order elastic constants and density ρ. In this study temperature dependent velocities in calcium oxide have been calculated along <100>, <110> and <111> crystallographic directions and the results are presented graphically and discussed in depth.

Keywords

Micro Structural Properties, Seismic and Volcanic Activities, Acoustic Wave Velocities, Second Order Elastic Constants.

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Kailash ¹, K. M. Raju ¹, S. K. Shrivastava ², S. Kushwaha ³

Affiliations
1 Department of Physics, Brahmanand Post-Graduate College, Rath, Hamirpur-210431, UP, IN
2 Institute of Basic Sciences, Bundelkhand University, Jhansi-284128, UP, IN
3 Department of Physics, Pt. J.N. P.G. College, Banda-210001, UP, IN

Abstract

An effort has been made for obtaining the second order elastic constants of rocksalt structure solids starting from primary physical parameters viz. nearest neighbour and hardness parameter assuming long- and short-range potentials at an elevated temperature. When the values of the second order elastic constants are known for a crystal, many of the anharmonic properties of the crystal can be treated within the limit of the continuum approximation in quantitative manner. The ultrasonic velocity any crystal is directly related to their second order elastic constants (v-longitudianal=(C₁₁/d)^1/2, v-shear=(C₄₄/d)^1/2;d is density). In this study, second order elastic constants are computed upto their melting temperature for rocksalt structure solids, which are alkali cyanides, sodium and potassium halides. The results thus obtained are compared with experimental data and found in well agreement with present values.

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S. K. Shrivastava ¹

Affiliations
1 Department of Physics, Bundelkhand University Jhansi, Jhansi-284128, IN

Abstract

The 13th National Symposium on Ultrasonics (XIII NSU 2004) was organized jointly by Department of Physics, Bundelkhand University, Jhansi and Ultrasonics Society of India (USI), National Physical Laboratory, New Delhi during December 21-23, 2004. The Symposium was an effort to bring to-gather all active researchers, users of Ultrasonics and Industrialists engaged in manufacturing ultrasonic equipments. Dr. Krishan Lai, Former Director, NPL inaugurated the Symposium. The inaugural session was presided over by Prof. P.S. Bisen, Dean, Academic Development & Planning, Bundelkhand University, Jhansi. Dr. Krishan Lal, President of USI released the Souvenir. Dr. S.K. Shrivastava gave the welcome address. Dr Krishan Lai, Prof. P.S. Bisen addressed the delegates and other invitees. Dr Janardan Singh, General Secretary, USI also addressed and spoke on the activities of USI and introduction about XIII-NSU 2004. Dr. Kailash, Co-convener, gave the vote of thanks. Beautiful mementoes were also presented to the Guests in the inaugural function. In spite of very cold weather, large number of participants participated from different parts of the country.

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