Journal of Pure and Applied Ultrasonics

Sanjay H. Bagade ¹, V. M. Ghodki ¹, Gopesh K. Singh ²

Affiliations
1 Janki Devi Bajaj Science College, Wardha-442001, IN
2 Anand Niketan College, Warora-442907, IN

Abstract

The Hooke's law is perfectly obeyed in perfectly elastic solids, where even a small amplitude wave can propagate with undiminished amplitude and intensity. But, most of the real solids show a deviation from perfectly elastic behaviour, and exhibit "anharmonicity". As a result, a high frequency acoustic wave travelling through real solids gets attenuated. In present work, on the basis of theory of elasticity and making use of higher order elastic constants in solids some aspects of elastic and acoustic properties of semiconductor silicon are studied. Assuming a temperature dependent lattice parameter and non-linearity parameter, D_L, the acoustic wave attenuation is calculated. The losses leading to attenuation are attributed to phonon-phonon interactions. Theoretically calculated values of D_L and attenuation are compared with experimental values of D_L and attenuation obtained by W.P. Mason. A good agreement between the theoretical and experimental values proves the correctness of our approach.

Keywords

Acoustic Wave Attenuation, Longitudinal Waves, Elastic Constants.

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S. Rajagopalan ¹, S. J. Sharma ², V. M. Ghodki ³

Affiliations
1 Department of Electronics, Nagpur University Campus, Nagpur-440 010, IN
2 Department of Electronics, S. K. Porwal College, Kamptee, Nagpur-441 002, IN
3 Department of Electronics, J. B. Science College, Wardha-442 001, IN

Abstract

The most popular and effective technique for ultrasonic velocity measurements is the pulse technique. In the present work, a computer based single-pulse sender/receiver technique is designed in the laboratory using indigenous components and a PCL-812 ADC card. A program written in C controls the pulse generation, detection and travel time measurement. An r.f. burst of 2 MHz of 5μS width is obtained from the ADC card. This pulse is amplified and sent to the transmitting transducer. The received pulse is detected and processed by the ADC card for determining the travel time and displays the ultrasonic velocity of propagation in the system on the computer screen. The system developed in the laboratory has been tested for the ultrasonic velocity measurements in different standard liquids. It has been found that the ultrasonic velocity measurements carried out using the above system matches well with those reported in the literature.

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