Iskanje po katalogu digitalne knjižnice

Opis: ▫$BaTiO_3$▫ ceramics were exposed to fluorine-containing atmosphere prepared by introducing a fluorination agent (▫$CF_3CH_2OH$▫) into a hot alumina-tube furnace. The fluorinated samples were studied using SEM and TEM. The fluorination resulted in the formation of a surface-reaction layer with a complex structure. At the reaction front fluorine reacts with ▫$BaTIO_3$▫ to produce ▫$BaF_2$▫ and ▫$BaTi_2O_5$▫. During the course of the fluorination the ▫$BaTi_2O_5$▫ reacts further to produce ▫$BaF_2$▫ and then subsequently Ba-polytitanates with an increasing content of titanium, and then finally ▫$TiO_2$▫. Fluorine also diffuses along the grain boundaries towards the pellet's interior. The presence of the fluorine stabilises the ▫$BaTi_2O_5$▫ compound and consequently triggers its formation in the ceramic's interior in a reaction between ▫$BaTiO_3$▫ and the intergranular phase ▫$Ba_6Ti_{17}O_{40}$▫.
Ključne besede: ceramics, fluorinated ceramic samples, stabilising, electronic ceramics
Objavljeno v DKUM: 10.07.2015; Ogledov: 1148; Prenosov: 120
Celotno besedilo (1,20 MB)
Gradivo ima več datotek! Več...