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In the present research article, the acoustic shock wave-resistant efficiency of silica microparticles (SiO 2 -α-cristobalite)) has been experimentally evaluated in terms of structural, optical and morphological stability against the impact of shock waves. The required SiO 2 particles were synthesized by a hydrothermal method which was subjected to a different number of shock pulses such as 200,400 and 600 with Mach number 2.2. Shocked samples' structural, morphological and optical stabilities have been evaluated by utilizing a powder X-ray diffractometer (PXRD), Ultraviolet–Diffuse reflectance spectrometer (DRS) while the surface morphological analysis has been scrutinized by the field emission scanning electron microscopic technique (FESEM) and transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy techniques are utilized to evaluate oxidation states and crystallographic structural stability. The above-mentioned analytical techniques provide convincing proofs whereby the synthesized SiO 2 particles are authentically proven to possess outstanding structural, optical and morphological stability against the impact of shock waves. The implicated experimental results and the arguments strongly suggest that the SiO 2 particles are suitable candidates for aerospace and defense industry applications due to their outstanding shock wave-resistant properties. [ABSTRACT FROM AUTHOR]

In this context, we report the acoustic shock wave processing on amorphous Carbon quantum dots (a-CQD) such that its degree of graphitization and magnetic properties are analyzed. Analytical techniques such as the Raman spectrometer, high resonation–transmission electron microscopy (HR-TEM) and vibrating sample magnetometer (VSM) are utilized to understand the structural, morphological and magnetic properties changes under shocked conditions. The Raman spectroscopic data reveal that the I D /I G ratio is slightly reduced under shocked conditions and the observed values are 0.78, 0.77 and 0.75 for the respective 0, 150 and 300 shocked conditions. The formation of ultra-short-range graphitic nanostructures is confirmed by HR-TEM results at the 300-shocked condition. The most convincing and supporting results for the enhancement of the degree of graphitization are found by the outcome of the magnetic properties such that the saturation magnetization (Ms) is found to be linearly reduced with respect to the number of shock pulses and the observed values are 0.869, 0.757 and 0.710 emu/g for the 0, 150 and 300 shocked conditions, respectively. The electrical resistance of the a-CQD is found to be linearly reduced with respect to the number of shock pulses due to the reduction of sp3 carbon networks. The formation of crystalline graphitic nanostructures in amorphous CQD is explained on the basis of the hot-spot nucleation mechanism. Based on the obtained Raman, HR-TEM and VSM results, during the shocked conditions, slight enhancement of the graphitization is observed; however, from the structural stability point of view, the Carbon dots have high shock resistance than that of the amorphous carbon nanoparticles, multi-wall carbon nanotubes, and reduced graphene oxide nanoparticles. Hence, the title quantum dots can be strongly considered for the applications of device fabrication. [ABSTRACT FROM AUTHOR]

• Crystallographic phase stability of L-alanine at shocked conditions is reported. • Structure—chirality property relationship of the test sample is discussed. • The titled materials can be potential candidate for the device applications. • Shock wave physics can be an alternative technique to find the stable materials. Over the years, crystallographic phase transitions of the polar and non-polar amino acids under static high-pressure-temperature conditions have been well documented, especially after the development of the diamond anvil cell techniques. In contrast, the crystallographic structural science of such primary amino acids under dynamic shocked conditions is still to be explored substantially as it is in a premature stage which requires being loaded with a few possible deep insights whereby exploring the structural kinetics could be a reality. In the present context, we have performed the acoustic shock wave recovery experiment on non-polar amino acid of L-Alanine powder samples such that X-ray diffraction (XRD) and circular dichroism (CD) spectroscopic techniques have been enabled to investigate the structural and chiral stability under shocked conditions. Based on the observed results, it is observed that the crystallographic structure with the P 2 1 2 1 2 1 space group and the same chirality is maintained even at the 200-shocked condition with a transient pressure of 2.0 MPa. The observed dynamic shock wave loading structural stability outcome is identified to be well-matched with the previous static high-pressure compression results. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The structure-properties relationship of crystalline and amorphous state of NiSO 4 ·6H 2 O sample is investigated. • Melting points of the crystalline and amorphous samples are identified to be 156.40 and 128.6 °C, respectively. • Amorphous state of NiSO 4 ·6H 2 O possesses higher electrical conductivity compared to the crystalline counterpart. • The values of magnetization for crystalline and amorphous samples are found to be 0.7339 and 2.070 emu/g, respectively. In the present work, we report the phase transition from crystalline to amorphous (topological disorder) of NiSO 4 ·6H 2 O (NSH) for which impedance spectroscopic and differential scanning calorimetric (DSC) techniques have been utilized to understand the changes in a better way thereby the electrical and thermal properties could be identified. According to the observed dielectric properties, the crystalline NSH has a low dielectric constant and low electrical conductivity whereas both of these values are high for the obtained amorphous state. DSC thermograms provide crystal clear details for the cause of the witnessed changes wherein the melting point region changes for both the crystalline and the amorphous samples. The values of magnetization for crystalline and amorphous samples are found to be 0.7339 and 2.070 emu/g, respectively. Because of the effective switchability between crystalline and amorphous states, the NSH crystal is suggested for the applications of sensors and dielectric switches. [ABSTRACT FROM AUTHOR]