Nanocomposites and nanomaterials

Preparation and optical properties of phosphotungstate nanostructured glass-ceramics
Chornii V.P.1,2, Boyko V.V.1, Nedilko S.G.2, Terebilenko K.V.2, Zozulia V.O.2, Slobodyanik M.S.2, Sheludko V.I.3, Gomenyuk O.V.3   
1National University of Life and Environmental Sciences of Ukraine. Geroiv Oborony st., 15, Kyiv-03041, Ukraine. 
E-mail: vchornii@gmail.com, vchornii@nubip.edu.ua. 
2 Taras Shevchenko National University of Kyiv, Volodymyrs’ka st., 60, Kyiv-01601, Ukraine.
3Oleksandr Dovzhenko Hlukhiv National Pedagogical University, Kyjevo-Moskovs’ka st, 24, Hlukhiv-41400, Ukraine.

The luminescent glass-ceramics (GC), those are mostly the composites with crystalline phosphors inside of glass host, appear to be very promising materials for light emission sources [1]. Such materials can be obtained by co-sintering, sol-gel, glass crystallization or some other techniques. Among them, the advantage of glass crystallization technique is related with close composition of glass and crystalline components that decreases a light scattering in GC. The optical quality of GC depends strongly on composition of the glass host and size of crystalline grains. Phosphate-based glasses are known to be transparent in visible spectral range and can be considered as good host for GC elaboration. Depending on glass modifiers (Bi2O3, MoO3, WO3, etc) there are many oxide compounds which can be crystallized in such glass systems – phosphates, molybdates, tungstates and some other of mixed anion compounds. 
In this work the glass-ceramics those consist of K2O-P2O5-WO3-V2O5 glass and K2Eu(PO4)(WO4) micro/nanocrystallites were prepared and studied. The samples of GC were characterized by means of powder X-ray diffraction, thermogravimetric analysis (DTA), scanning electron microscopy, energy dispersive X-ray analysis, infrared vibration, absorption and luminescence electron-vibration spectroscopy. 
The results have showed that studied glass ceramics are perspective luminescent materials for white LED applications.

1.	Ren X., Pei M., Ming C., Zhou A. Ju D., Song F. Stable temperature characteristic of phosphate glass ceramic for white light-emitting diode // Micro & Nano Letters.-2019.-14.-P. 113-115.