Transparent glass ceramics containing Lu6
O5
F8
:Tb3+
 nano-crystals: Enhanced photoluminescence and X-ray excited luminescence

Transparent phosphosilicate glass-ceramics were prepared by heating the spontaneously crystallized precursor glasses in which crystals have formed during cooling of the melts. And the effects of compositional variation on the crystalline phases, degree of crystallization and transparency were investigated by using X-ray diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). It is found that Mg2+tends to exist in silicate-rich phase rather than phosphate-rich phase, such MgO is more beneficial to the transparency of phosphosilicate glass-ceremics compared to CaO. In addition, the substitution of P2O5for SiO2enhances the tendency of phase separation, and hence the precipitation of Na2MgSiO4crystals for the precursor glasses as well as glass-ceramics with good transparency.

Download Full-text

Temperature-Controlled Devitrification of Oxyfluoride Borate Glasses

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.130.263 ◽

2007 ◽

Vol 130 ◽

pp. 263-266 ◽

Cited By ~ 3

Author(s):

Joanna Pisarska ◽

Tomasz Goryczka ◽

Wojciech A. Pisarski

Keyword(s):

Heat Treatment ◽

Glass Ceramics ◽

Borate Glasses ◽

X Ray Diffraction ◽

Transparent Glass ◽

X Ray ◽

Heat Treated ◽

Before And After ◽

Controlled Crystallization ◽

Temperature Controlled

Selected oxyfluoroborate glasses have been investigated before and after heat treatment. Transparent glass-ceramics (TGC) were obtained during controlled crystallization (devitrification). X-ray diffraction studies confirmed that material was partially crystallized. Diffraction lines due to orthorhombic PbF2 phase were identified for heat-treated samples at various temperatures and times. Results were compared to that ones obtained for as-melted glass.

Download Full-text

Highly enhanced photoluminescence and X-ray excited luminescence of Li doped Gd2O3:Eu3+ thin films

Solid State Communications ◽

10.1016/j.ssc.2005.10.018 ◽

2006 ◽

Vol 137 (3) ◽

pp. 162-165 ◽

Cited By ~ 19

Author(s):

Xiaolin Liu ◽

Bingjie Liu ◽

Mu Gu ◽

Lihong Xiao ◽

Xin Xu

Keyword(s):

Thin Films ◽

X Ray ◽

Enhanced Photoluminescence ◽

Excited Luminescence

Download Full-text

The Microstructure of Steatite (Protoenstatite)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118102 ◽

1985 ◽

Vol 43 ◽

pp. 236-237

Author(s):

W. E. Lee ◽

A. H. Heuer

Keyword(s):

High Frequency ◽

Glass Ceramics ◽

Magnesium Silicate ◽

Beam Current ◽

Glassy Matrix ◽

Angle Of Incidence ◽

X Ray ◽

Mechanical And Electrical Properties ◽

Argon Ions ◽

High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

Download Full-text