Assessment of crystallographic and electronic phase stability of shock wave loaded cubic cerium oxide nanoparticles

Sivakumar, A.; Ramya, S.; Dhas, S. Sahaya Jude; Almansour, Abdulrahman I.; Kumar, Raju Suresh; Arumugam, Natarajan; Murugesan, Magesh; Dhas, S. A. Martin Britto

doi:10.1016/j.ceramint.2021.09.281

Cited by 13 publications

(5 citation statements)

References 31 publications

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“…But, at the second shocked condition, there is a shoulder band that is located at the region of lower frequency and it could be because of the existence of the distortion as well as the disorder of the SO 4 ions. [ 56 ] It could be noted that such kind of shoulder Raman band doesn't appear in any other shocked conditions. In Figure 8, Raman spectral regions of both the ammonium ions NH 4 (I) and NH 4 (II) corresponding to the pristine and shocked crystals are presented wherein considerable changes are observed under shocked conditions.…”

Section: Resultsmentioning

confidence: 99%

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Acoustic Shock‐Wave‐Induced Crystallographically Order–Disorder Switchable Phase Transition of Ammonium Sulfate Crystal: X‐Ray Diffraction and Raman Spectroscopic Approach

Aswathappa,

Palaniyasan,

Sathiyadhas

et al. 2024

Physica Status Solidi (b)

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In this framework, the authors have intended to examine the phase‐transition probability of ammonium sulfate (NH4)2SO4 under dynamic shock loaded conditions, whereby it is authenticated from the observations that the title crystal undergoes the process of reversible phase transition of crystallographic nature. The observed phase‐transition sequence is Pnam (crystalline) → Pnam (crystalline) → distorted Pnam (semicrystalline) → Pnam (crystalline) → Pnam (crystalline) under the exposure of 0, 1, 2, 3, and 4 shocks, respectively, such that the order of the transition is evaluated by diffraction and spectroscopic techniques. The obtained differential scanning calorimetry and thermogravimetric analysis results provide the crystalline‐state ammonium sulfate which has higher thermal stability than that of the disordered‐state ammonium sulfate. Analyzing the acquired results of the analytical experiments, the authentication can be arrived at such that the phase transition of reversible nature is enforced by the molecular distortions followed by the occurrence of rotational disorder involving ammonium and sulfate groups of ions influenced by the impulsion of shock waves thereby the title crystal can be a potential material for molecular switching applications.

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Section: Resultsmentioning

confidence: 99%

“…Note that, from the observed results, it is obvious that the lowering of endothermic peak positions occurs due to the formation of crystallographic disorder structure and similar kinds of results have been found for the NiSO 4 ·6H 2 O crystal. [ 56,67 ]…”

Section: Resultsmentioning

confidence: 99%

Acoustic Shock‐Wave‐Induced Crystallographically Order–Disorder Switchable Phase Transition of Ammonium Sulfate Crystal: X‐Ray Diffraction and Raman Spectroscopic Approach

Aswathappa,

Palaniyasan,

Sathiyadhas

et al. 2024

Physica Status Solidi (b)

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“…23−29 Only a few studies on technologically significant nanoparticles have been published thus far, but they have produced some intriguing findings such as crystallographic phase transitions (TiO 2 , ZrO 2 ), 23,24 molecular phase transitions (α-Fe 2 O 3 , Co 3 O 4 ), 25,26 magnetic phase transitions (CoFe 2 O 4 , ZnFe 2 O 4 ), 27,28 crystalline to amorphous (SiO 2 ), 29 amorphous to crystalline (multiwall carbon nanotubes) 30 whereas, in some other cases, stable crystal structures and morphologies have been observed. 31,32 In addition to the structural aspects, a few interesting results have been observed in the electrochemical properties. For instance, in the case of MWCNTs, the specific capacitance for the control, 150 and 300 shocks-loaded CNTs are found to be 196, 215, and 294 F g −1 , respectively, at 100 mV s −1 .…”

Section: Introductionmentioning

confidence: 99%

“…The processing of the nanoparticles by static high pressure and laser shock waves has an extensive track record in recent decades. − However, the knowledge of how acoustic shock waves interact with nanomaterials is still at its formative level, and only a few articles have been published thus far. , Acoustic shock waves may have more influence on promoting nanostructures than laser shock waves and static high-pressure techniques despite the fact that there are many postprocessing technologies available for this purpose. The experimental outcomes of tabletop pressure-driven shock tubes have recently made it possible to analyze the characteristics of materials at pressures of several bars and temperatures of a few thousand Kelvin. , The dynamic recrystallization induced by shock waves leads to changes in morphology, magnetic phase shifts, material deformation, and electronic structure, crystallographic and molecular structural properties. − Only a few studies on technologically significant nanoparticles have been published thus far, but they have produced some intriguing findings such as crystallographic phase transitions (TiO 2 , ZrO 2 ), , molecular phase transitions (α-Fe 2 O 3 , Co 3 O 4 ), , magnetic phase transitions (CoFe 2 O 4 , ZnFe 2 O 4 ), , crystalline to amorphous (SiO 2 ), amorphous to crystalline (multiwall carbon nanotubes) whereas, in some other cases, stable crystal structures and morphologies have been observed. , In addition to the structural aspects, a few interesting results have been observed in the electrochemical properties. For instance, in the case of MWCNTs, the specific capacitance for the control, 150 and 300 shocks-loaded CNTs are found to be 196, 215, and 294 F g –1 , respectively, at 100 mV s –1 .…”

Section: Introductionmentioning

confidence: 99%

Acoustic Shock Wave-Induced Solid-State Fusion of Nanoparticles: A Case Study of the Conversion of One-Dimensional Rod Shape into Three-Dimensional Honeycomb Nanostructures of CdO for High-Performance Energy Storage Materials

Aswathappa,

Dai,

Jude Dhas

et al. 2023

Inorg. Chem.

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Herein, we describe the solid-state fusion of rod-shaped to honeycombshaped cadmium oxide particles (CdO NPs) caused by the process of repeated exposure to acoustic shock waves. Significant changes have been observed in structurally and morphologically dependent properties. For instance, at the 200-shocked condition, the high-pressure CdO-B2 phase is present as a secondary phase wherein all of the rodshaped particles have been transformed into honeycomb-shaped CdO particles which possess comparatively higher specific-capacitance than CdO nanorods (NRs). The computed specific capacitance values for the 0, 100, and 200 shocked samples at a scan rate of 100 m V s −1 are computed to be 433, 415, and 583 F g −1 , respectively. The second-stage decomposition temperature points of the CdO NPs have significantly increased in accordance with the morphological changes from rod to honeycomb patterns such that the values are 343, 526, and 534 °C, respectively, for 0, 100, and 200 shocked conditions. Note that such honeycomb nanostructured CdO particles by shock-wave processing have never been observed, to date. Due to the superior energy storage abilities as well as the spectacular high thermal stability of the honeycomb CdO nanostructures compared to CdO NRs, shocked CdO with honeycomb nanostructures can be considered as energy storage materials.

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“…For example, CeO 2 is a metal oxide used as a humidity sensor, but also as a catalyst, a solid electrolyte in fuel cells, a high-temperature ceramic, coating, etc. [ 3 , 4 , 5 , 6 ]. For sensing application, the composition of materials is, of course, critical, but morphologically the nanometer dimension of a particle constituent also plays a beneficial role in the advancement of sensing properties, by providing a large specific surface area and pore volume [ 7 ].…”

Section: Introductionmentioning

confidence: 99%

Humidity Sensing Ceria Thin-Films

Mandić¹,

Bafti²,

Pavić

et al. 2022

Nanomaterials

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Lowering the constitutive domains of semiconducting oxides to the nano-range has recently opened up the possibility of added benefit in the research area of sensing materials, in terms both of greater specific surface area and pore volume. Among such nanomaterials, ceria has attracted much attention; therefore, we chemically derived homogeneous ceria nanoparticle slurries. One set of samples was tape-casted onto a conducting glass substrate to form thin-films of various thicknesses, thereby avoiding demanding reaction conditions typical of physical depositions, while the other was pressed into pellets. Structural and microstructural features, along with electrical properties and derivative humidity-sensing performance of ceria thin-films and powders pressed into pellets, were studied in detail. Particular attention was given to solid-state impedance spectroscopy (SS-IS), under controlled relative humidity (RH) from 30%–85%, in a wide temperature and frequency range. Moreover, for the thin-film setup, measurements were performed in surface-mode and cross-section-mode. From the results, we extrapolated the influence of composition on relative humidity, the role of configuration and thin-film thickness on electrical properties, and derivative humidity-sensing performance. The structural analysis and depth profiling both point to monophasic crystalline ceria. Microstructure analysis reveals slightly agglomerated spherical particles and thin-films with low surface roughness. Under controlled humidity, the shape of the conductivity spectrum stays the same along with an increase in RH, and a notable shift to higher conductivity values. The relaxation is slow, as the thickness of the pellet slows the return of conductivity values. The increase in humidity has a positive effect on the overall DC conductivity, similar to the temperature effect for semiconducting behavior. As for the surface measurement setup, the thin-film thickness impacts the shape of the spectra and electrical processes. The surface measurement setup turns out to be more sensitive to relative humidity changes, emphasized with higher RH, along with an increase in thin-film thickness. The moisture directly affects the conductivity spectra in the dispersion part, i.e., on the localized short-range charge carriers. Moisture sensitivity is a reversible process for thin-film samples, in contrast to pellet form samples.

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Assessment of crystallographic and electronic phase stability of shock wave loaded cubic cerium oxide nanoparticles

Cited by 13 publications

References 31 publications

Acoustic Shock‐Wave‐Induced Crystallographically Order–Disorder Switchable Phase Transition of Ammonium Sulfate Crystal: X‐Ray Diffraction and Raman Spectroscopic Approach

Acoustic Shock‐Wave‐Induced Crystallographically Order–Disorder Switchable Phase Transition of Ammonium Sulfate Crystal: X‐Ray Diffraction and Raman Spectroscopic Approach

Acoustic Shock Wave-Induced Solid-State Fusion of Nanoparticles: A Case Study of the Conversion of One-Dimensional Rod Shape into Three-Dimensional Honeycomb Nanostructures of CdO for High-Performance Energy Storage Materials

Humidity Sensing Ceria Thin-Films

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