Hierarchical micro-nanostructured albite-based glass-ceramic for high dielectric strength insulators

Structural insights of hierarchically engineered feldspars by confocal Raman microscopy

“…According to the microstructure of the fast‐sintered glass–ceramic (Figure a) different distribution of stress could be expected. These differences should generate subtle alterations in Raman spectrum.…”

“…According to Table , in these Raman modes are involved cage‐shear movements in which rotations of tetrahedral along with Na + translation take place. Taking into account that the electrical conductivity mechanism o of this material occurs by a hopping mechanism , it may be established that the temperature increase activates the diffusion process of cations with high mobility, such as Na + or Ca 2+ , which strongly enhance the cage‐shear modes of this material . Raman modes between 600 and 900 cm −1 are softened, and therefore, the raise of temperature only reduces the force constant of the bond for tetrahedra as correspond to the increase in thermal agitation of the crystal.…”

“…The Na‐rich glass–ceramic material was prepared by a conventional ceramic process as described in previous works . Chemical composition of precursors, Kaolin, and frit, is expressed in terms of equivalent oxides in Table .…”

“…Recently, a novel glass–ceramic material based on Na‐rich albite type feldspar has been sintered having a high crystallinity, >94%, following a conventional ceramic process . This material possesses a hierarchical micro‐nanostructure in which nanostructured regions isolate micrograins.…”

“…Nanostructured regions contain nanograins and rest of vitreous phase. All of these features favour scattering processes of phonon, photon, and electron in the material, which are the origin of low thermal conductivity, high ultraviolet, visible, and near infrared reflectivity and the largest breakdown strength reported for a glass–ceramic material . However, to a whole understanding of the excellent thermal, optical, and electric properties a complete characterization of the feldspar under study is necessary.…”