Controlled Phase Changes of Titania Using Nitrogen Plasma

Abstract

In this work, the development of a new crystallization technique is reported, using nitrogen plasma (AC) to obtain nanostructured anatase and rutile from amorphous titanium oxide (TiO2). This methodology increases throughput and minimizes thermal effects. Nanostructured amorphous TiO2 was obtained by the sol-gel method and subsequently subjected to AC treatment, at a controlled pressure, applying different powers and treatment times in order to obtain phase changes. The obtained samples were characterized using X-ray diffraction (XRD), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The results show the crystallization in parallel with anatase and rutile phases with a proportion that is directly related to the applied power in the plasma and the treatment time. This technique allows us to obtain smaller crystals in comparison with those of classic thermal methodologies. It is also demonstrated that the application of plasma represents a novel and innovative method to obtain phase polymorphic changes in titanium oxide without needing to apply prolonged heat treatments at high temperatures and can therefore be taken into consideration as a technique with low energy costs, in comparison with conventional heat treatments.

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

“…Figure shows the TGA profiles of the control and shocked Li 2 SO 4 samples presented with respect to the number of shock pulses and the TGA thermogram provides the distinct weight loss features of the crystalline and the amorphous state samples; Figure shows a clear indication of the formation of crystalline Li 2 SO 4 (β-Li 2 SO 4 ) is witnessed. In general, the crystalline specimen exhibits a uniform weight loss with respect to temperature up to reaching the decomposition point, whereas the disordered samples show nonuniform weight loss with respect to temperature. − Based on the previous reports, as in Figure , it is possible to witness a uniform weight loss from 165.5 to 780 °C only at the second shocked condition, which gives strong supportive evidence for the formation of the crystalline specimen only at the second shocked condition.…”

One-step nitrogen plasma process for bimetallic impregnation to obtain N-TiO2−X/Au/Ag composite

“…7,8 Similarly, the process of plasma treatment has been successful in inducing phase changes on amorphous TiO 2 . 9 In this work, we reported positive results in bimetallic impregnation by applying nitrogen plasma technique, and this new proposal could contribute to improvement of novel processes in the search of new nanocomposite.…”

Crystal Growth by Unidirectional Method ‐ A Generalized View on the Crystalline Perfection of the Uni‐Indexed, Bi‐Indexed, and Tri‐Indexed Plane Single Crystals

“…Moreover, the tri‐indexed plane samples’ tangent area is comparatively high that clearly substantiates the highly disordered nature of the crystal. [ 62–65 ]…”

“…Moreover, the tri-indexed plane samples' tangent area is comparatively high that clearly substantiates the highly disordered nature of the crystal. [62][63][64][65] In addition to that, the observed XRD patterns of the uniindexed, bi-indexed and tri-indexed plane crystals that have been grown by slow evaporation growth technique at ambient temperature are presented in Figure 11. As seen in Figure 11, all the uni-indexed, bi-indexed and tri-indexed plane crystals have good crystalline nature of long-range order.…”