Rahman, Mohammad Mahbubur (2009) Investigation of the effect of uniaxial stress on the elastic properties of Rb₄LiH₃(SO₄)₄. Masters thesis, Memorial University of Newfoundland.
- Accepted Version
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In this project, ultrasonic measurements have been used in order to observe the influence of uniaxial stress on the elastic properties of the ferroelastic compound Rb₄LiH₃(SO₄)₄. The experimental results are compared to predictions derived from a Landau model. In the experiment, uniaxial stresses either along  or  direction have been applied using two piezo-actuators mounted on opposite faces of the crystal. The temperature and pressure ranges for this investigation arc 100 - 150K and 0 - 0.27 kbar, respectively. Throughout the investigation, it has been observed that in the absence of stress, the sound velocity along the x and z -axes shows a distinct step-like variation in the vicinity of the transition temperature, Tc = 134 K. The amplitude of the step-like variation is found to decrease with the application of a uniaxial stress. We believe that this is principally due to a reconfiguration of the domain distribution into the ferroelastic phase. This is supported by our Landau model which predicts no large variation over this pressure range.
|Item Type:||Thesis (Masters)|
|Additional Information:||Includes bibliographical references (leaves 98-102).|
|Department(s):||Science, Faculty of > Physics and Physical Oceanography|
|Library of Congress Subject Heading:||Axial loads; Crystals at low temperatures; Ferroelastic crystals--Elastic properties|
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