A Comparative Investigation on the Structural Stability of the Single and Poly-Crystalline Sodium Nitrate at Dynamic Shock Wave Loaded Conditions

Exploration of the structural stability of the single and poly-crystalline materials of solid-state at high temperature and pressure is one of the basic research topics in the materials science branch. While the initial state of material undergoes change because of external factors, the functional properties of the material are usually significantly varied and hence, detailed investigations are highly required to better understand either change in properties or stability of materials with respect to their initial states. En route to this process, the crystallographic phase stability of sodium nitrate poly-crystalline samples are studied at dynamic shocked conditions and the observed results are compared to the previously reported sodium nitrate single crystal. The structural stability profile of the test sample is assessed by X-ray diffraction, Raman spectroscopic and optical spectroscopic techniques. Surface morphology features are obtained from the scanning electron microscopic (SEM) technique. The overall observation of the diffraction, spectroscopic and morphological analyses shows that the poly-crystalline sodium nitrate sample has higher stability than that of the single crystal of sodium nitrate. The detailed interpretations are presented in the following sections.