Composition–property relationships of the La2O3–Al2O3–SiO2 glass system

Mullite crystallization kinetics of lanthanum doped sol–gel derived precursors

“…La 2 O 3 as a network modifier increases the number of non-bridging oxygen atoms in the amorphous structure, and consequently favors the diffusion and phase separation processes during the thermal treatment of the gels. 27 The localized compositional changes due to the phase separation ultimately preclude formation of stoichiometric mullite, but in favor of metastable alumina-rich mullite.…”

27Al NMR Studies of Aluminosilicate Glasses

“…Compared with their M (2) O-Al 2 O 3 -SiO 2 analogs, RE AS glasses exhibit enhanced physicochemical properties (such as lower corrosion resistance, higher glass-transition temperature and microhardness [271][272][273]) that traditionally have been attributed to the relatively strong RE-O bonds. However, on the basis of a strong observed correlation between the Vickers hardness and the Al average coordination number in a large set of RE 2 O 3 -Al 2 O 3 -SiO 2 (RE¼La, Y, Lu, Sc) glasses of widely spanning compositions, we recently proposed a new explanation for the well-known microhardness enhancement of RE AS glasses when the RE 3+ CFS is increased [89,270]: it originates from the concurrent growth of the AlO 5 populations and their enhanced network cross-linking effects through relatively strong Al [5] -OSi [4] /Al [4] bonds.…”

The broadband NIR emission properties of Bi doped La2O3–Al2O3–SiO2 glass

“…Compared with M-O bondstrengths of alkali-and alkali-earth-based glasses, La-O bonds are stronger due to the high field-strength of La 3 þ ion. Similar to yttrium-aluminum-silicate glass which was studied by Hughes et al [31], Lanthanum aluminosilicate glasses exhibit high glass transition temperatures ranging roughly between 800 and 900 1C, which is virtually independent of glass composition [21]. The excellent physical properties and lower optical basicity make lanthanum aluminosilicate glasses to be potential hosts for bismuth doping.…”