Pressureless Crystallization of Glass for Transparent Nanoceramics

Abstract

Transparent nanoceramics embedded with highly dense crystalline domains are promising for applications in missile guidance, infrared night vision, and laser and nuclear radiation detection. Unfortunately, current nanoceramics are strictly constrained by the stringent construction procedures such as super‐high pressure and containerless processing. Here, a pressureless crystallization engineering strategy in glass for elaboration of transparent nanoceramics and fibers is proposed and experimentally demonstrated. By intentional creation of a sharp contrast between nucleation and growth rates, the crystal growth rate during glass crystallization can be significantly suppressed. Importantly, this unique phase‐transition habit enables the achievement of transparent nanoceramics and even smooth fibers with extremely tiny crystalline size (≈20 nm) and high crystallinity (≈97%) under atmospheric pressure. This allows the generation of an attractive nonlinear optical response such as dynamic optical filtering and luminescence in the mid‐infrared waveband of 4300–4950 nm. These findings highlight that the strategy to switch the phase‐transition habit of glass into the unconventional crystallization regime may provide new opportunities for the creation of next‐generation nanoceramics and fibers.

Enhanced 2 µm Mid‐Infrared Laser Output from Tm3+‐Activated Glass Ceramic Microcavities

“…[ 42 ] While the enhancement of the intensity at 109 cm −1 indicates the increase of [BiO 6 ] and [BiO 3 ] units. [ 43 ] TEM image of the GC microsphere obtained at a heat treatment temperature of 395 °C reveals that the precipitated nanocrystals are homogeneously dispersed in the glass host with a distributed diameter of 16–27 nm, which are consistent with the calculated result from the XRD data (Figure 3c,d). The HR‐TEM image of a single nanoparticle shows the crystal lattice stripes with a d‐spacing of 0.33 nm that matches well with the (111) plane of Bi 2 Te 4 O 11 crystals (Figure 3e).…”

“…[ 39 ] The band at around 400 cm −1 is associated with the bending modes of Te–O–Te linkages, [ 40 ] and the band located around 109 cm −1 is related to the vibration modes of Bi 3+ in [BiO 3 ] or [BiO 6 ] groups. [ 41,43 ] Notably, the Raman intensity at 655 and 400 cm −1 decrease after crystallization, which reflects that the precipitation of Bi 2 Te 4 O 11 nanocrystals in glass phase leads to the destruction of Te–O–Te linkages in a continuous glass network and a part of Te is replaced by Bi. [ 42 ] While the enhancement of the intensity at 109 cm −1 indicates the increase of [BiO 6 ] and [BiO 3 ] units.…”

Enhanced CW Lasing and Q‐Switched Pulse Generation Enabled by Tm3+‐Doped Glass Ceramic Fibers

“…[ 35 ] Meanwhile, the Raman intensity at 109 cm −1 rises, manifesting the increase in the number of [BiO 3 ] and [BiO 6 ] units. [ 36 ] The microstructure changes of fibers are consistent with the behavior of the bulk glasses under the same heat‐treatment conditions. Furthermore, for the fiber cladding after heat treatment, no sharp Raman band can be detected, confirming its amorphous state.…”

High-security-level multi-dimensional optical storage medium: nanostructured glass embedded with LiGa5O8: Mn2+ with photostimulated luminescence

“…Glass can be perceived as a 'supercooled liquid' in a thermodynamically metastable state, so it tends to crystallize upon the supply of appropriate thermal energy. However, controlled glass crystallization remains arduous, as nucleation and growth stages usually overlap with each other 38 . Only when the nucleation rate is boosted and the growth rate is suppressed can ordered crystal-in-glass nanocomposites with high transparency be obtained, as in the present case ( Fig.…”