Structure and crystallization behavior of mixed potassium-lithium niobiosilicate glasses

Influence of the Devitrification Mechanism on Second Harmonic Generation Efficiency and Transparency in Ba2NaNb5O15Nanostructures

“…On the other hand, the Raman spectrum of BaNaNS-Iexo exhibits a narrow band centered at 634 cm –1 confirming the formation of more ordered and symmetric NbO 6 octahedra such as in the Ba 2 NaNb 5 O 15 phase. On the basis of the above data and according to the previous studies concerning the crystallization behavior of potassium , and mixed-alkali niobiosilicate glasses, , it is possible to assert that the crystallization of BaNaNS glass takes place as a consequence of phase separation and, consequently, it can be driven and controlled by proper thermal treatment in the glass transition range.…”

“…Hence great interest is devoted to the research of SHG active phases that show bulk nucleation. Tetragonal tungsten–bronze (TTB) phases are a family of noncentrosymmetric crystals that show large SHG efficiencies. − Recently, we have obtained TTB phases by bulk nucleation from KNS glasses with K partially substituted by Li and Na. , Particularly, glass ceramics based on a new potassium sodium niobate crystalline phase with tungsten–bronze structure have been obtained from 8­K 2 O·­15Na 2 ­O·27Nb 2 O 5 ·50­SiO 2 and 13K 2 O·10­Na 2 O·27­Nb 2 O 5 ·50SiO 2 glasses showing SHG efficiencies about 10 –3 times greater than β-BaB 2 O 4 (BBO) powders . Barium-containing TTB phases, such as Ba 2 KNb 5 O 15 and Ba 2 NaNb 5 O 15 (BNN), generate great interest as a consequence of their excellent electro-optic and nonlinear optical properties. , Particularly, BNN has been used in frequency-doubling applications because of its conversion efficiency and resistance to optical damage superior to those of other known materials such as LiNbO 3 .…”

“…9−11 Recently, we have obtained TTB phases by bulk nucleation from KNS glasses with K partially substituted by Li and Na. 12,13 Particularly, glass ceramics based on a new potassium sodium niobate crystalline phase with tungsten−bronze structure have been obtained from…”

Toward an ideal nanomaterial for on-chip Raman laser

“…The process, involving two partially overlapped processes, namely, phase separation and crystallization, produces a transparent material. [52][53][54] In order to obtain transparent nanostructured glasses, it is necessary that amorphous or crystalline phase grows from the glass exclusively with a bulk nucleation mechanism. By means of a proper nucleation heat treatment, it is possible to produce a high number of bulk nuclei and, consequently, a high number of nanocrystals small enough to avoid any light scattering.…”