Energetics of oxidation of RE–Si–Al–O–N glasses

2003 ◽  
Vol 18 (7) ◽  
pp. 1607-1613 ◽  
Author(s):  
Yahong Zhang ◽  
Alexandra Navrotsky ◽  
Dirk Matusch ◽  
Hans Jürgen Seifert
Keyword(s):  
Glass Transition ◽  
Rare Earth ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Nitrogen Content ◽  
Ionic Radius ◽  
Composition Range ◽  
Enthalpies Of Formation ◽  
Acid Base ◽  
Nitrogen Ions

Enthalpies of drop solution in molten 52 wt.% LiBO2-48 wt.% NaBO2 at 1078 K were measured for RE1.1Si1.7Al0.6O6-1.5xNx (x = 0, 0.2, 0.4, 0.6, 0.8) glasses for RE = Nd, Gd, Dy, Er, and Y. Linear relations between enthalpies of formation from elements and nitrogen content indicate that, within the experimental composition range, sites occupied by nitrogen ions are approximately equivalent in energy for a given substitutional series. The energetics of different rare-earth SiAlON glasses appears to be dominated by differences in the acid/base character of the cations. The onset glass-transition temperature increases linearly with increasing nitrogen content for the same rare earth and with decreasing rare-earth ionic radius for the same nitrogen content.

The Glass Transition Temperature of Iron and Titanium Containing Phosphate Based Glasses

2015 ◽  
Vol 1115 ◽  
pp. 178-181
Author(s):  
S.I.S. Shaharuddin ◽  
I. Ahmed ◽  
D. Furniss ◽  
A.J. Parsons ◽  
Chris D. Rudd
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Field Strength ◽  
Ionic Radius ◽  
Phosphate Content ◽  
Scanning Calorimetry ◽  
Amorphous Nature ◽  
Glass Series

In this study various compositions in the phosphate based glass (PBG) system of (50-x)P2O5-40Ca-(5+x)Na-5TiO2 and (50-x)P2O5-40Ca-(5+x)Na-5Fe2O3, where x= 5 and 10 were investigated for glass transition temperature (Tg) via thermo mechanical analyser (TMA) and differential scanning calorimetry (DSC). The amorphous nature of the glasses was confirmed via XRD. The Tg measured via DSC was consistently higher by 19°C-29°C compared to TMA and was due to the thermal history and the heating rate of the samples. The Tg increased with increasing phosphate content in both glass systems. The Tg for Ti containing PBG was found to be in the range of 453°C-500°C whilst Tg for Fe containing PBG was in the range of 449°C-494°C. Consistently higher Tg for the Ti containing glass series compared to the Fe containing glasses may be attributed to the smaller ionic radius and therefore higher field strength of Ti4+.

Nitridation of Bioresorbable Phosphate Glass

1996 ◽  
Vol 455 ◽  
Author(s):  
H. Jiang ◽  
W. C. Lacourse
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Nitrogen Content ◽  
Phosphate Glass ◽  
Ph Value ◽  
Chemical Durability ◽  
Anhydrous Ammonia

ABSTRACTThe bioresorbable 10CaO·35Na2O·55P2O5 glass was nitrided by melting the glass under anhydrous ammonia. The nitrided glasses were fiberized at about 720 °C in air. The dynamic and the equilibrium pH value of the glass increases with the increase of nitrogen content. The incorporation of nitrogen not only increases the glass transition temperature, but also improves the chemical durability and makes it easier to fiberize. Further more, the nitrided glass is more resistant to devitrification.

Rare Earth Elements on Glass-Forming Ability and Thermal Stability of Cu-Zr-Al Metallic Glass

2011 ◽  
Vol 688 ◽  
pp. 426-430 ◽  
Author(s):  
Yan Fang Wang ◽  
Li Li ◽  
Chuan Sun ◽  
Qing Long Lu ◽  
Zhi Qiang Shi
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Rare Earth ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Metallic Glass ◽  
Rare Earth Elements ◽  
Glass Forming Ability ◽  
Glass Forming ◽  
Thermal Stability Of

The rare earth elements (RE= Y, Sm, La, Ce) were used as alloying materials in Cu50Zr45Al5BMG, and their influences on the glass-forming ability and thermal stability were studied in this paper. All the samples remained in full metallic glass state with minor additions of Y, Sm and La. Increasing the amount of RE additions, the Cu10Zr7and Zr2Cu phases precipitated and glass transition temperatureTgand crystallization temperatureTxsignificantly decreased. The reduced glass transition temperature Trg=Tg/Tlranged from 0.592 to 0.611 and the γ parameter ranged from 0.393 to 0.409.

Preparation and structure of organic-inorganic hybrid low-melting phosphite glasses from phosphonic acid H3PO3

2003 ◽  
Vol 18 (5) ◽  
pp. 1081-1086 ◽  
Author(s):  
Haruki Niida ◽  
Masahide Takahashi ◽  
Takashi Uchino ◽  
Toshinobu Yoko
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Phosphonic Acid ◽  
Acid Base ◽  
Inorganic Hybrid ◽  
Average Linkage ◽  
Nuclear Magnetic Resonance Spectra ◽  
Si Content

An organic–inorganic, hybrid, low-melting glass free of pollution elements such as Pb and F was prepared through nonaqueous acid-base reactions of Si—Cl + P—OH ⇉ Si—O—P + HCl⇈ and Sn—Cl + P—OH ⇉ Sn—O—P + HCl⇈ using phosphonic acid (H3PO3), dimethyldichlorosilane (Me2SiCl2), and tin(II)chloride (SnCl2) as starting materials. Transparent, colorless, and homogeneous phosphite glass was successfully obtained. The formation of P—O—Si linkage and the disappearance of P—OH were confirmed by 31P nuclear magnetic resonance spectra. With increasing Si content, the glass-transition temperature decreased, reflecting the decrease of the average linkage number per one cation.

Bulk Scandium-based Metallic Glasses

2005 ◽  
Vol 20 (9) ◽  
pp. 2243-2247 ◽  
Author(s):  
X.K. Xi ◽  
S. Li ◽  
R.J. Wang ◽  
D.Q. Zhao ◽  
M.X. Pan ◽  
...  
Keyword(s):  
Glass Transition ◽  
Rare Earth ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Metallic Glasses ◽  
Elastic Moduli ◽  
Supercooled Liquid ◽  
The Novel ◽  
Casting Method ◽  
Mold Casting

The novel rare-earth scandium-based bulk metallic glasses (BMGs) are obtained by the copper mold casting method. Compared with other rare-earth BMGs reported so far, the Sc-based BMGs exhibit the highest elastic moduli (e.g., Young’s modulus, E = 85 GPa; bulk modulus, B = 77.5 GPa), glass transition temperature (Tg = 662 K), and crystallization temperature (Tx = 760 K) combined with a large region of supercooled liquid (ΔT = 98 K). A good correlation between glass transition temperature and elastic moduli is found in a variety of rare-earth-based BMGs.

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