Dynamic Shock Wave-Induced Switchable Phase Transition of Magnesium Sulfate Heptahydrate

Abstract

To date, even though a large number of shock wave induced irreversible crystal-crystal phase transitions have been reported for the past few decays, switchable phase transitions of solid state materials by dynamic shock waves remain to be quite un-known and also attainment of switchable phase transitions is somewhat a difficult task as compared to the irreversible phase transitions. Hence, experiments on switchable phase transition arising out of materials and the related publications are always considered to be valuable asserts for the materials researchers so as to master over the enhanced understanding of the behavior of materials and their probable applications. Moreover, materials of switchable phase have enormous number of spectacular industrial applications. In the present framework, we have presented and demonstrated the switchable phase transition of magnesium sulfate heptahydrate (MgSO4.7H2O) at shocked conditions and the switching behavior has been screened by diffraction, vibrational spectroscopic ACCEPTED MANUSCRIPT -CLEAN COPY 2 and optical spectroscopic techniques so as arrive at X-ray diffraction (XRD), Raman scattering and UV-Visible spectral analyses, respectively. All the observed results clearly reveal that the switchable phase transition is achieved at dynamic shock wave loaded conditions. The interesting aspects of the present experimental results with respect to the number of shock pulses are discussed in the upcoming sections.

Dynamic Shock Wave-Induced Amorphous-to-Crystalline Switchable Phase Transition of Lithium Sulfate

“…But the doublet Raman bands at υ 4 and υ 2 regions become singlet, which indicates the enhancement of rotational disorder of the SO 4 tetrahedron, leading to the amorphous nature of the test sample. Note that in the case of dynamic shocked conditions and high-pressure compression conditions, SO 4 anionic units are found to have undergone significant rotational order–disorder effects, and such results have been well documented. − …”

High Shock Resistance of Polycrystalline Sodium Sulfate Crystals at Dynamic Shocked Conditions

“…Recently, our research group has reported the shock wave induced phase transition of mixed phase to pure phase and pure phase to mixed phase with respect to the number of shock pulses of 1 and 2, respectively. [ 21 ] More importantly, single‐crystalline samples of sodium sulfate crystals show the crystallographic phase response with respect to the number of shock pulses following the sequence of F ddd– F ddd– C mcm– F ddd– F ddd for the respective 0, 1, 2, 3, and 4 shocked conditions and the corresponding XRD patterns are presented in Figure 1b. [ 31 ] In addition to that, the XRD patterns of the zoomed‐in versions of the control and shocked samples are presented in Figure 2 wherein no remarkable change is found either in the diffraction peak shift or in the diffraction peak intensity with respect to the number of shock pulses.…”

“…Moreover, the observed results broadly depend on the starting materials which are either in single crystalline or in polycrystalline states. [11,[16][17][18][19][20] For example, the reports on starting materials of bulk-single-crystalline samples such as sapphire, [16] potassium dihydrogen phosphate, [17] glycine phosphite, [18] pentaerythritol tetranitrate (PETN), [19] potassium sulfate, [20] magnesium sulfate heptahydrate, [21] and cyclotrimethylene trinitramine (RDX); [22] the bulk-polycrystalline sample such as ammonium dihydrogen phosphate, [23] potassium dihydrogen phosphate, [17] glycine phosphite, [24] potassium sulfate, [25] and magnesium bromide; [26] and nanocrystalline materials such as titanium oxide, [27] zirconium oxide, [28] cerium oxide, and cobalt oxide reflect the abovementioned features convincingly. [29,30] Based on the previous reports, the outcomes of the shock wave impact analyses also reveal that the mode of changes is dependent on the nature of the starting materials such as single-crystalline, bulk-polycrystalline, and nanosized polycrystalline states as well as the value of transient pressure of the shock waves and the number of shock pulses.…”

Acoustic Shock Wave-Induced Amorphous to Crystalline Phase Transitions of Li2SO4─Raman Spectroscopic and Thermal Calorimetric Approach

“…Dynamic shock wave-induced structural phase transitions such as polymorphic and order–disorder-type phase transitions on molecular crystals continue to be one of the active research topics in recent years, and several interesting results have been established in different groups of anionic materials such as anhydrate sulfates, − hydrated sulfates, − and nitrates , of bulk single crystals. An important research endeavor that is essential to comprehending the molecular nature and mechanism of structural changes in classical solids is the study of phase transitions on sulfates under shocked conditions.…”