Sol-gel synthesis of oxygen-ion conductors based on apatite-structure silicates and silicophosphates

Direct synthesis of La9.33Si6O26 ultrafine powder via sol–gel self-combustion method

“…Therefore, several techniques have been developed to get active ultra-fine La 9.33 Si 6 O 26 powders with apatite-type structure [3,[5][6][7][8].…”

Spectral characteristics of germanium compounds having apatite structure

“…Anion-substituted apatites with the general formula M 10À x Ln x (SiO 4 ) x (PO 4 ) 6À x O 2 are particular about synthesis conditions; for instance, it was found that impurity phases such as Ca 4 P 2 O 7 are precipitated if required temperature and duration of annealing are not observed [5]. The series of solid solutions M 2 Ln 8 (SiO 4 ) 6À x (PO 4 ) x O 2 is limited because at x40.15 the phase LnPO 3 is precipitated from the basic structure [6].…”

“…One of these positions (6h) has a point group of symmetry C S and is coordinated by six chemically bound oxygen ions and by one so-called "free oxygen". The second position (4f) is surrounded by 9 6 O 2 are characterized by the presence of OH À hydroxogroups in the oxygen channels, which reduces the reaction stability of functional materials [5]. Anion-substituted apatites with the general formula M 10À x Ln x (SiO 4 ) x (PO 4 ) 6À x O 2 are particular about synthesis conditions; for instance, it was found that impurity phases such as Ca 4 P 2 O 7 are precipitated if required temperature and duration of annealing are not observed [5].…”

Sol-gel synthesis and spectral characteristics of crystal phosphors Sr2Y8(1 − x)Eu8x Si6O26

“…In the present work, 4 and metal nitrates were used as initial components. Indi vidual phases of Sr 2 Eu 8 Si 6 O 26 and Sr 2 Y 8 Si 6 O 26 sili cates were prepared through interaction of strontium nitrate and rare earth element (REE) nitrate with TEOS in acidic solutions containing water and ethyl alcohol at a ratio Sr : Eu(Y) : Si = 2 : 8 : 6.…”

“…In this case, the formed salts decomposed with NO 2 emis sion. Upon thorough stirring, powders were annealed for 14 h consecutively at temperatures 800, 900, 1000, 1100, and 1200°C [4,5].…”