The phase transition of Co3O4 into CoO is demonstrated by the impact of shock waves, and the mechanism is studied and reported. The required quantity of Co3O4 nanoparticle (NPs) is synthesized by coprecipitation method. 2.0 MPa transient pressure shock wave is utilized to understand the shock wave induced phase transition in Co3O4 NPs. XRD and Raman studies reveal that the phase transition occurs at 150 shocks in loaded condition. The obtained values of optical band gap energy show that there are changes in band gap energy with respect to the number of shock pulses. SEM images portray that the surface morphology and shape of the particles are considerably changed by the impact of shock waves due to the dynamic recrystallization. Vibrating sample magnetometer (VSM) shows the switchable magnetic phase transition from superpara–para–superpara magnetic behavior. The mechanism of the shock wave induced phase transition is described.

In this research article, the shock wave induced switchable phase transition (β to α and α to β) of potassium sulfate (K 2 SO 4 ) crystal is demonstrated. The test crystals are subjected to shock waves of one pulse and two pulses, respectively, and their crystallographic properties are compared with the control test sample. Fourier transform Raman spectroscopy (FT-Raman), ultraviolet−visible spectroscopy (UV−vis), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and dielectric studies are performed to understand the reversible phase transformation of potassium sulfate crystal enabled by the impact of shock waves. The bulk grain resistance (R g ) and capacitance C g values of control K 2 SO 4 crystal, post first shock, and second shock at room temperature are observed to be 88 MΩ, 92 MΩ, and 88 MΩ and 84 pF, 23 pF, and 84 pF, respectively. The dielectric relaxation time (τ g ) reveals the fact that the phase reversal occurs after the second shock. The values of τ g for control K 2 SO 4 crystal, post first shock, and second shock are calculated to be 7.39, 2.10, and 7.39 ms, respectively. The crystallographic and analytical studies reveal that the sample β-K 2 SO 4 is transformed to α-K 2 SO 4 during the first shock pulse loaded condition, and it comes back to the phase of β-K 2 SO 4 as and when loaded with the second shock pulse.

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According to the available sources obtained from the literature survey to date, shock wave induced switchable phase transition is yet to be understood concretely as compared to the irreversible phase...

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