scholarly journals Structure and Properties of Piezoelectric Strontium Fresnoite Glass-Ceramics Belonging to the Sr–Ti–Si–Al–K–O System

Ceramics ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 86-97 ◽  
Author(s):  
Marie-Sophie Renoirt ◽  
Nathalie Maury ◽  
Florian Dupla ◽  
Maurice Gonon
Keyword(s):  
Glass Ceramic ◽  
Mirror Symmetry ◽  
Glass Ceramics ◽  
Preferential Orientation ◽  
Surface Crystallization ◽  
High Temperature Xrd ◽  
Crystallization Conditions ◽  
The Stability ◽  
Oriented Parallel

Crystallization of strontium fresnoite Sr2TiSi2O8 piezoelectric crystals in Sr–Ti–Si–K–Al–O parent glasses is investigated with the aim of showing the influence of composition and crystallization conditions on the microstructure and piezoelectric properties of the resulting glass-ceramic. All the investigated conditions lead to a surface crystallization mechanism that induces a preferential orientation of crystal growth in the glasses. Near the surface, all the glass-ceramics obtained exhibit (002) planes preferentially oriented parallel to their faces. Deeper in the specimens, this preferential orientation is either kept or tilted to (201) after a depth of about 300 µm. The measurement of the charge coefficient d33 of the glass-ceramic highlights that surface crystallization induces mirror symmetry in the polarization. It reaches 11 to 12 pC/N and is not significantly influenced by the preferential orientation (002) or (201). High temperature XRD shows the stability of the fresnoite phase in the glass-ceramics up to 1000 °C. Mechanical characterization of the glass-ceramics by impulse excitation technique (IET) highlights that the softening of the residual glass leads to a progressive decrease of Young’s modulus in the temperature range 600–800 °C. Damping associated to the viscoplastic transition become severe only over 800 °C.

Novel Glass-Ceramics for Dental Application by Sol Gel Technique

2008 ◽  
Vol 396-398 ◽  
pp. 153-156 ◽  
Author(s):  
Xanthippi Chatzistavrou ◽  
E. Hatzistavrou ◽  
Nikolaos Kantiranis ◽  
Lambrini Papadopoulou ◽  
Eleana Kontonasaki ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Preparation Method ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Dental Restorations ◽  
Gel Technique ◽  
Gel Preparation ◽  
Dental Applications ◽  
Potential Use

The aim of this study was the fabrication using a sol-gel technique of a new glass-ceramic with potential use in dental applications. The characterization of the composition and microstructural properties of the produced material confirmed the similarity between the new sol-gel derived glass-ceramic and a commercial leucite based fluorapatite dental glass-ceramic. The produced material has potential application in dental restorations and it is expected to exhibit better control of composition, microstructure and properties due to the intrinsic advantages of the sol-gel preparation method.

HIPed Tailored Pyrochlore-Rich Glass-Ceramic Waste Forms for the Immobilization of Nuclear Waste

2008 ◽  
Vol 1124 ◽  
Author(s):  
Melody Lyn Carter ◽  
Hui Li ◽  
Yingjie Zhang ◽  
Andrew L Gillen ◽  
Eric R Vance
Keyword(s):  
Nuclear Waste ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Spectroscopic Characterization ◽  
Chemical Durability ◽  
Intermediate Level ◽  
Crystalline Phases ◽  
Waste Forms ◽  
Ceramic Samples

AbstractHot isostatically pressed (HIPed) glass-ceramics for the immobilization of uranium-rich intermediate-level wastes and Hanford K-basin sludges were designed. These were based on pyrochlore-structured Ca(1-x)U(1+y)Ti2O7 in glass, together with minor crystalline phases. Detailed microstructural, diffraction and spectroscopic characterization of selected glass-ceramic samples has been performed, and chemical durability is adequate, as measured by both MCC-1 and PCT-B leach tests.

Structure Characterization of Sintered CaO-Al2O3-SiO2 Glass-Ceramic Reinforced with Spodumene

2013 ◽  
Vol 834-836 ◽  
pp. 309-314
Author(s):  
Zi Fan Xiao ◽  
Jin Shu Cheng ◽  
Jun Xie
Keyword(s):  
Glass Ceramic ◽  
Energy Dispersive Spectrometry ◽  
Crystal Size ◽  
Bending Strength ◽  
Glass Ceramics ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray

A glass-ceramic belonging to the CaO-Al2O3-SiO2(CAS) system with different composition of spodumene and doping the Li2O with amount between 0~2.5 % (mass fraction) were prepared by onestage heat treatment, under sintering and crystallization temperature at 1120 °C for two hours. In this paper, differential thermal analysis, X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry and bending strength test were employed to investigate the microstructure and properties of all samples. β-wollastonite crystals were identified as the major crystalline phases, and increasing Li2O was found to be benefit for the crystallization and tiny crystalline phases remelting, resulting in the content of major crystalline phases increased first and then decreased with increasing the expense of spodumene. Meanwhile, the crystal size can be positively related with the content of Li2O. The preferable admixed dosage of spodumene can be obtained, besides the strength of glass-ceramics can be more than 90 MPa.

scholarly journals Effects of Sintering Temperature Variation on Synthesis of Glass-Ceramic Phosphor Using Rice Husk Ash as Silica Source

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5413
Author(s):  
Rabiatul Adawiyah Abdul Wahab ◽  
Mohd Hafiz Mohd Zaid ◽  
Sidek Hj. Ab Aziz ◽  
Khamirul Amin Matori ◽  
Yap Wing Fen ◽  
...  
Keyword(s):  
Rice Husk ◽  
Glass Ceramic ◽  
Rice Husk Ash ◽  
Glass Ceramics ◽  
Xrd Analysis ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Silica Source ◽  
Quenching Method

In this study, the authors attempted to propose the very first study on fabrication and characterization of zinc-boro-silicate (ZBS) glass-ceramics derived from the ternary zinc-boro-silicate (ZnO)0.65(B2O3)0.15(RHA)0.2 glass system through a conventional melt-quenching method by incorporating rice husk ash (RHA) as the silica (SiO2) source, followed by a sintering process. Optimization of sintering condition has densified the sintered samples while embedded beta willemite (β-Zn2SiO4) and alpha willemite (α-Zn2SiO4) were proven in X-ray diffraction (XRD) analysis. Field emission scanning electron microscopy (FESEM) has shown the distribution of willemite crystals in rhombohedral shape crystals and successfully form closely-packed grains due to intense crystallization. The photoluminescence (PL) spectra of all sintered ZBS glasses presented various emission peaks at 425, 463, 487, 531, and 643 nm corresponded to violet, blue, green, and red emission, respectively. The correlation between the densification, phase transformation, microstructure, and photoluminescence of Zn2SiO4 glass-ceramic phosphor is discussed in detail.

In Vitro Bioactivity Characterization of Machinable Glass Ceramics Containing 85wt% Na-mica and 15wt% Fluorapatite

2006 ◽  
Vol 309-311 ◽  
pp. 325-328 ◽  
Author(s):  
Gültekin Göller ◽  
Ipek Akin ◽  
A. Kahraman ◽  
Erdem Demirkesen ◽  
M. Urgen
Keyword(s):  
Thin Film ◽  
Heat Treatment ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Xrd Analysis ◽  
Crystallization Time ◽  
In Vitro Bioactivity ◽  
Treatment Procedures

In this study; in-vitro bioactivity characterization of machinable glass-ceramics having 85 wt% sodium mica (NaMg3AlSi3O10F2) and 15 wt% fluoroapatite has been carried out. Two different heat treatment procedures are applied to the machinable glass-ceramics. The first one is nucleation at 610°C for 2 hours and crystallization at 1000°C for 3 hours and the second is nucleation at 610°C for 2 hours and crystallization at 1000°C for 4 hours. It is observed that increasing the crystallization time to 4 hours resulted in the increasing the formation of hydroxyapatite layer on surface. According to the microstructural investigations, the morphology of the precipitated crystals are different. In addition, the speed of the precipitation of hydroxyapatite is higher in glass-ceramic B than A. Thin film XRD analysis supports these results.

Preparation and Characterization of SrO-Na2O-Fe2O3-FeO-P2O5-SiO2 Ferrimagnetic Glass-Ceramics for Hyperthermia Application

2012 ◽  
Vol 557-559 ◽  
pp. 1612-1617
Author(s):  
Jian An Liu ◽  
Xue Na Yang ◽  
Mei Mei Zhang ◽  
Wen He
Keyword(s):  
Aqueous Solution ◽  
Saturation Magnetization ◽  
Electric Furnace ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Vibrating Sample Magnetometer ◽  
Specific Saturation Magnetization ◽  
Heat Treated ◽  
Molecular Scale

The ferrimagnetic glass-ceramic based on SrO-Na2O-Fe2O3-FeO-P2O5-SiO2 system was prepared for hyperthermia application using aqueous aolution-melt method. Using the aqueous solution solvent evaporation, we obtained the molecular-scale homogenously glass precursor. The precursor was completely melted in a lidded platinum crucible placed in an electric furnace at 1480°C for 1h and then annealed in a furnace at 550°C for 40min.The annealed glasses were heat treated at 1050°C for 1h to obtain the glass-ceramics. The crystallization of the glass systems with different component has been systematically investigated by using XRD, TEM, as well as vibrating sample magnetometer (VSM). The glass-ceramics with P2O5=5.0wt% show a strong magnetic, which contains highest value of specific saturation magnetization of 24.89A•m2/kg.

Application of DSC Technique in Study of Glass Ceramic

2010 ◽  
Vol 105-106 ◽  
pp. 743-745
Author(s):  
Li Jie Qu ◽  
Bin Li ◽  
Jing Wang ◽  
Yue Mei Gu
Keyword(s):  
Activation Energy ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Differential Scanning Calorimetric ◽  
Isothermal Method ◽  
Practical Applications ◽  
Activation Energy Of Crystallization ◽  
Optimum Heat ◽  
The Stability

Glass-ceramics with desired microstructures and properties are controlled by nucleation and crystallization. The nucleation and crystallization of glass, which include the nucleation, crystal growth rates and the activation energy, are important in understanding the stability of glass in practical applications. The activation energy of crystallization (E) plays an important role in determining the utility of glass ceramic. The amorphous to crystalline transformation in glass can be investigated by isothermal and non-isothermal method which is differential scanning calorimetric (DSC). In the isothermal method, the sample is measured as a function of time, while in the non-isothermal method the sample is recorded as a function of temperature. An advantage of the non-isothermal method is the possibility of reaching a test temperature instantaneously and during the time, which system needs to stabilize. However, the isothermal method does not have this advantage. In the present work, this technique was used to calculate the activation energy of CaO-Al2O3-SiO2-CeO2 glass-ceramics. DSC technique can be used as to determine the optimum heat treatment temperature. The advantage of the DSC technique in study of glass-ceramics is that it requires much less time.

Preparation and Characterization of Sro-Na2O-Fe2O3-P2O5-SiO2 Ferrimagnetic Glass-Ceramics for Hyperthermia Application

2012 ◽  
Vol 581-582 ◽  
pp. 457-462
Author(s):  
Jian An Liu ◽  
Xue Na Yang ◽  
Mei Mei Zhang ◽  
Wen He
Keyword(s):  
Aqueous Solution ◽  
Magnetic Properties ◽  
Magnetic Property ◽  
Glass Ceramic ◽  
Room Temperature ◽  
Glass Ceramics ◽  
Vibrating Sample Magnetometer ◽  
Heat Treated ◽  
Molecular Scale

The ferrimagnetic glass-ceramic based on SrO-Na2O-Fe2O3-P2O5-SiO2 system was prepared for hyperthermia application using aqueous aolution-melt method. Using the aqueous solution solvent evaporation, we obtained the molecular-scale homogenously glass precursor. The precursor was completely melted in a lidded platinum crucible placed in an electric furnace at 1480°C for 1h and then annealed in a furnace at 550°C for 40min.The annealed glasses were heat treated at 1050°C for 2h to obtain the glass-ceramics. The crystallization of the glass systems with different component has been systematically investigated by using XRD. Room temperature magnetic property of the samples were investigated using a Vibrating Sample Magnetometer(VSM). The evolution of magnetic properties in these glasses as a function of P2O5 quality concentration was discussed.

scholarly journals Shear Performance at Room and High Temperatures of Glass–Ceramic Sealants for Solid Oxide Electrolysis Cell Technology

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 298 ◽  
Author(s):  
Hassan Javed ◽  
Antonio Sabato ◽  
Ivo Dlouhy ◽  
Martina Halasova ◽  
Enrico Bernardo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Ceramic ◽  
Volume Fraction ◽  
Glass Ceramics ◽  
Solid Oxide ◽  
Electrolysis Cell ◽  
Solid Oxide Electrolysis ◽  
Key Factor ◽  
Solid Oxide Electrolysis Cell ◽  
The Stability

To provide a reliable integration of components within a solid oxide electrolysis cell stack, it is fundamental to evaluate the mechanical properties of the glass–ceramic sealing materials, as well as the stability of the metal–glass–ceramic interface. In this work, the mechanical behavior of two previously developed glass–ceramic sealants joined to Crofer22APU steel is investigated at room temperature, 650 °C, and 850 °C under shear load. The mechanical properties of both the glass–ceramics showed temperature dependence. The shear strength of Crofer22APU/glass–ceramic/Crofer22APU joints ranged from 14.1 MPa (20 °C) to 1.8 MPa (850 °C). The elastic modulus of both glass–ceramics also reduced with temperature. The volume fraction of the crystalline phases in the glass–ceramics was the key factor for controlling the mechanical properties and fracture, especially above the glass-transition temperature.

scholarly journals Effect of Partial Ba Substitutions on the Crystallization of Sr2TiSi2O8 (STS) Glass–Ceramics and on the Generation of a SAW Signal at High Temperatures

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4648
Author(s):  
Maurice Gonon ◽  
Florian Dupla ◽  
Hassan Alhousseini ◽  
Marc Duquennoy ◽  
Nikolay Smagin ◽  
...  
Keyword(s):  
High Temperatures ◽  
Glass Ceramic ◽  
Acoustic Waves ◽  
High Stability ◽  
Surface Acoustic Waves ◽  
Glass Ceramics ◽  
Preferential Orientation ◽  
Ceramic Substrates ◽  
Saw Devices ◽  
Ba Substitution

Because of their characteristics, including a d33 of 10–15 pC/N and high stability up to temperatures over 1000 °C, polar glass–ceramics containing fresnoite crystals can be regarded as highly effective materials for applications requiring piezoelectricity at high temperatures. In the present paper we investigate barium substitutions in an Sr-fresnoite (STS) glass–ceramic. Two aspects are studied: first, the effect of the substitution on the preferential orientation of the crystallization, and second, the ability of the glass–ceramics to generate and propagate surface acoustic waves (SAW) at high temperatures. XRD analyses show that a 10 at.% substitution of Ba allows us to keep a strong preferential orientation of the (00l) planes of the fresnoite crystals down to more than 1 mm below the surfaces. Higher substitution levels (25 and 50 at.%), induce a non-oriented volume crystallization mechanism that competes with the surface mechanism. SAW devices were fabricated from glass–ceramic substrates with 0, 10 and 25 at.% Ba substitutions. Temperature testing reveals the high stability of the frequency and delay for all of these devices. The glass–ceramic with a 10 at.% Ba substitution gives the strongest amplitude of the SAW signal. This is attributed to the high (00l) preferential orientation and the absence of disoriented volume crystallization.

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