The erf3doped oxyfluoride phospho tellurite glasses in the 40x teo210p2o545 baf2znf2 5na2oxerf3 system where x 0. Differential thermal analysis dta has been performed to measure glass transition and crystallization temperatures. Glass ceramics have an amorphous phase and one or more crystalline phases and are produced by a socalled controlled crystallization in contrast to a spontaneous crystallization, which is usually not wanted in glass manufacturing. We present combined results of optical, scattering, and spectroscopic studies of k2o15nb2o515teo270 glass and glass ceramic and comment on possible mechanisms of the optical behavior in terms of existing theory. Focusing on thermal, elastic, acoustic, electrical, and optical properties, this second edition incorporates the latest scientific data and uptodate applications of tellurite glass. I think that, heat treatment relaxes the glass structure by. The various physical parameters of the studied glasses will be estimated. Controlled crystal growth measurements using the xray line broadening technique for samples heat treated in the temperature range of 583693 k were carried out and compared with the photoluminescence.
Pdf structural characteristics and dielectric response of. The glass ceramic is confirmed to generate secondharmonic light. Improvement of spectroscopic properties and luminescence of. In this paper we report the effect of heat treatment of 10 mol% na2o89. On the basis of a structural interpretation of liquid immiscibility in binary oxide systems and of x. Optical implications of crystallite symmetry and structure in. Glass ceramics have the fabrication advantage of glass, as well as special properties of ceramics. Transparent oxyfluoride glassceramics containing caf2 nano. The present work deals with preparation of sodium niobium tellurite.
Ho2o3doped transparent tellurite glassceramics containing a metastable cubic crystalline phase were prepared. The structure of the glass and then the glassceramic was investigated by. The low temperature tellurite glass elaboration and its stability both enable the preparation of scalable tailor. The density of the studied glass ceramics increases by heat treatment. Doped glasses with rare earth ions have superior technological applications such as in fiber amplifiers, planar waveguides and display monitors of wavelengthconverting devices 1114. These precursor glasses have been prepared by melt quenching method in air, followed by thermal annealing at 550.
Combined neutron and xray diffraction data have been indexed to an orthorhombic unit cell a 3. Teo 2 and erpo 4 crystalline phases in the heated phosphotellurite glasses. Low coordination numbers, cornersharing rules imply that glass formation is more likely with open, low density polyhedral structures. A comprehensive study of the carbon contamination in tellurite glasses and glass ceramics sintered by spark plasma sintering sps. Transparent oxyfluoride tellurite glass with the composition of teo2sio2alf3caokf system were prepared by conventional melting and annealing technique, and the transparent oxyfluoride glass ceramics containing caf2 nanocrystallines were obtained by controlled heattreatment. Transparent oxyfluoride phospho tellurite glass ceramics containing cubic baf 2 nanocrystals were synthesized by heat treatment of the base glass containing 1.
Not only oxyfluoride tellurite glassceramic but also oxyfluoride. Physical properties and data, second edition covers the current dominant physical properties of this prototype glass system. Their success depend upon achieving a stable attachment to connective tissue. A series of glass samples based on the concentration of bismuth oxide with the following compositions 90 x. The glass is cooled down and is then reheated in a second step. Tissue attachment is directly related to the type of tissue. Structural, spectroscopic and magnetic properties of nd3. Ceramic to metal assemblies ceramic to metal assemblies. Glass transition, kinetics of crystallization and anomalous. Osa effect of nanoscale crystal field on the broadening of. Pdf structure of pbf2teo2 glasses and glassceramics.
The glass transition temperature is relevant to any solid that contains noncrystalline material. Generally, the stiffness decreases with temperature. Ceramic injection moulded components ceramic injection moulded components. Pdf xrd, sem, tem, raman and ftir have been used to study the structure of pbf2teo2 glasses and glassceramics 10. Optical properties and crystallization kinetic of tellurite. Quaternary tellurite glass systems in the form 75x teo2 20zno5na2co3 xer2o3 glass samples with 0. Spectroscopic studies of zno boratetellurite glass doped. Pdf optical properties and crystallization of bismuth borotellurite. The structural characteristics of a system of optically transparent xzno1. Spectroscopic properties of erbiumdoped oxyfluoride. Optical properties and crystallization kinetic of tellurite glassceramics nehal elkhoshkhany, alexandria university, egypt panel discussion and certificate distribution conference series llc 2360 corporate circle, suite 400 henderson, nv 890747722, usa ph.
Optical properties of bi2o3 doped boro tellurite glasses and glass. A comprehensive study of the carbon contamination in. V solidification vol meltvol cryst m e l t crystal glass supercooled volume liquid temperature tg t f tg slow fast glasses are frozen liquids. Review of tellurite glasses purification issues for mid. The complete book on glass and ceramics technology 2nd. We report a study based on the understanding of carbon contamination that is commonly observed. Pdf enhanced green upconversion by controlled ceramization. Electronic conductivity of vanadiumtellurite glassceramics.
Density, molar volume and oxygen packing density of every glass composition have been measured and calculated. In our previous work 26, a large 60 mm in diameter undoped tellurite glass sample was heat treated at 510 c for 1 h30, leading to a fully. In general, all four rules should be satisfied for glass formation to occur. Transparent oxyfluoride tellurite glass ceramics containing caf2 nanocrystals were prepared by high temperature melting method. The density of the prepared glass ceramic samples is larger than of the parent glass. The effect of erbium trifluoride addition on thermal, structure, and spectroscopic properties of oxyfluoride phospho tellurite precursor glass was studied by differential. Tellurite based glasses are wellknown for their upconversion properties besides having a disadvantage of low mechanical strength dragging them away from practical applications. Many studies on tertiary tellurite based glass have been done by various authors 916. Oct 20, 2016 innovative transparent tellurite polycrystalline ceramics are demonstrated to be simply elaborated by full and congruent crystallization of the 75teo 2 12.
This article is published with open access at abstract the glass transition temperature was. Mar 15, 2018 characterization of the fabricated tellurite ceramics. Silicate glasses are an exception elastic constants for glasses and glass ceramics code type e gpa g gpa 9606 glass ceramic 17. Jacers is a leading source for topquality basic science research and modeling spanning the diverse field of ceramic and glass materials science.
Only a few reported works show elaboration and optical properties characterizations of transparent tellurite glassceramics containing a high. Borotellurite glasses containing zno have a wide glass forming possibility and low ability to crystallize. Furthermore, transparent tellurite glass ceramics that contain ferroelectric crystalline phases have been shown to exhibit strong second harmonic generation 3, indicating the high potential of these glasses as new optical functional materials. Ceramics, glasses, and glassceramics zgenerally used to repair or replace skeletal hard connective tissue. They dont posses a distinct melting temperature but a glass transition temperature. The density values of glass ceramics have been estimated by eq. Spectroscopic properties of erbiumdoped oxyfluoride phospho. It has been noted previously1 that the elements which, in the form of their oxides, are generally regarded as excellent glass formers have values of electronegativity on the pauling scale2 of 1. Pdf new bismuth borotellurite glass within the compositions. References this glass material related article is a. Tellurite glasses contain tellurium oxide teo 2 as the main component. Optical properties of bi2o3 doped boro tellurite glasses. Pdf structural characteristics and dielectric response. First, a glass is formed by a glass manufacturing process.
Optical properties of bismuth tellurite based glass. The formation of pbte3o7 nanocrystals was confirmed by xray diffraction xrd and transmission electron microscope tem. Second harmonic generation in germanotellurite glass ceramics. Pdf a comprehensive study of the carbon contamination in. Best results are obtained under rich o 2 atmosphere with platinum crucibles although gibbs energy calculations show that other crucibles material are possible such as gold or. A tem study and nonisothermal crystallization kinetic of. In this heat treatment the glass partly crystallizes. For the production of glass ceramics, a high density of crystalline nuclei is generated in the glass melt either by the droplet phaseseparation mechanism or by the addition of nucleating agents such as titania, zirconia, and phosphorus pentoxide. The xray diffraction xrd analysis revealed the formation of 16 nm barium difluoride nanocrystals in the oxyfluoride phospho tellurite glass ceramics. Glass, chap 5 slide 6 material science ii vtdiagram for crystal and for glass formation. The glass ceramics were characterized by differential scanning calorimetry, xray diffraction and scanning electron microscope, respectively. Metals are difficult to keep from crystallizing but if quenched fast enough, they can exhibit noncrystalline phases.