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   https://doi.org/10.1039/c9ra04583j  

   Both, Avinash Kumar; Cheung, Chin Li (July 2019, RSC Advances)

   We report the growth of carbon dioxide (CO 2 ) whiskers at low temperatures (−70 °C to −65 °C) and moderate pressure (4.4 to 1.0 bar). Their axial growth was assessed by optical video analysis. The identities of these whiskers were confirmed as CO 2 solids by Raman spectroscopy. A vapor–solid growth mechanism was proposed based on the influence of the relative humidity on the growth. 

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2. Polymorphic control in titanium dioxide particles

   https://doi.org/10.1039/D2NA00390B  

   Quiñones Vélez, Gabriel; Soto Nieves, Diego; Castro Vázquez, Anushka; López-Mejías, Vilmalí (January 2023, Nanoscale Advances)

   The hydrolysis–condensation reaction of TiO 2 was adapted to the phase inversion temperature (PIT)-nano-emulsion method as a low energy approach to gain control over the size and phase purity of the resulting metal oxide particles. Three different PIT-nano-emulsion syntheses were designed, each one intended to isolate high purity rutile, anatase, and brookite phase particles. Three different emulsion systems were prepared, with a pH of either strongly acidic (H 2 O : HNO 3 , pH ∼0.5), moderately acidic (H 2 O : isopropanol, pH ∼4.5), or alkaline (H 2 O : NaOH, pH ∼12). PIT-nano-emulsion syntheses of the amorphous TiO 2 particles were conducted under these conditions, resulting in average particle diameter distributions of ∼140 d nm (strongly acidic), ∼60 d nm (moderately acidic), and ∼460 d nm (alkaline). Different thermal treatments were performed on the amorphous particles obtained from the PIT-nano-emulsion syntheses. Raman spectroscopy and powder X-ray diffraction (PXRD) were employed to corroborate that the thermally treated particles under H 2 O : HNO 3 (at 850 °C), H 2 O : NaOH (at 400 °C), and H 2 O : isopropanol (at 200 °C) yielded highly-pure rutile, anatase, and brookite phases, respectively. Herein, an experimental approach based on the PIT-nano-emulsion method is demonstrated to synthesize phase-controlled TiO 2 particles with high purity employing fewer toxic compounds, reducing the quantity of starting materials, and with a minimum energy input, particularly for the almost elusive brookite phase. 

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3. Thermal conductivity of rutile germanium dioxide

   https://doi.org/10.1063/5.0011358  

   Chae, S.; Mengle, K. A.; Lu, R.; Olvera, A.; Sanders, N.; Lee, J.; Poudeu, P. F.; Heron, J. T.; Kioupakis, E. (September 2020, Applied Physics Letters)

   null (Ed.)
4. Reconfigurable Reflectarray Unit Cell using Vanadium Dioxide

   https://doi.org/10.1109/APS/URSI47566.2021.9704486  

   Ramsey, Jordan A.; Henderson, Kendrick Q.; Ghalichechian, Nima (December 2021, 2021 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (APS/URSI))
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   https://doi.org/10.23919/EuCAP53622.2022.9768925  

   Ramsey, Jordan; Henderson, Kendrick; Ghalichechian, Nima (March 2022, 2022 16th European Conference on Antennas and Propagation (EuCAP))