INVESTIGATION ON THE EFFECT OF RARE EARTH (RE) CATION TO THE (RE+Ca)SiAlON GLASSES

Yıl 2012, Cilt: 13 Sayı: 2, 127 - 134, 31.01.2013

Cem Orhun Emrah Dölekçekiç

Öz

The main purpose of this study was to determine the change in density, glass transition temperature (Tg) and hardness as a result of compositional modifications in the (RE+Ca)SiAlON oxynitride glasses (RE= Er, Nd, Sm, Eu, Dy, Yb) with a cation ratio in eq% of (1+27):56:16 = (RE+Ca):Si:Al. The amount of nitrogen was kept constant (N=5 eq %).

Additionally other series of the (Er+Y):Si:Al:O:N glasses with cation composition  3+25):56:16 were prepared with different amount of nitrogen (where N= 0, 5, 10 eq %) to observe the effect of nitrogen to glass transition temperature. X-Ray diffraction patterns proved that all produced glasses were amorphous.

Tg and hardness results of (RE+Ca)SiAlON glasses were revealed that there is a linear relationship between cation field strength (CFS). Density results versus molecular weight and CFS were presented. Additionally, glass transition temperatures of the (Er+Y)SiAlON glasses were further increased with the increasing nitrogen content in the structure. These results are also compared with (RE+Ca)SiAlON glass series.

Anahtar Kelimeler

-

NADİR TOPRAK ELEMENTİ KATYONLARININ (RE+Ca)SiAlON CAMLARINA ETKİSİNİN İNCELENMESİ

Öz

Bu çalışmanın ana amacı katyon oranı eşdeğer yüzdece (eq %), (1+27):56:16=(RE+Ca):Si:Al olan
(RE+Ca)SiAlON oksinitrür camlarında yoğunluk, cam geçiş sıcaklığı ve sertlik değişimlerinin bile-
şimsel değişikliklere bağlı olarak incelenmesidir. (RE+Ca)SiAlON camlarının azot değerleri sabit tutulmuştur
(N=5 eq %).
Ayrıca, katyon bileşimi (3+25):56:16 olan (Er+Y):Si:Al camlar, azotun Tg’ye etkisini gözlemlemek
amacıyla farklı azot oranlarıyla hazırlanmıştır (N= 0, 5, 10 eq %).
(RE+Ca)SiAlON camlarının Tg ve sertlik sonuçları katyon alan mukavemeti (CFS) değerlerine
bağlı olarak lineer bir ilişkiyle açıklanmıştır. Yoğunluk sonuçları ise moleküler ağırlık ve CFS değerlerine
karşı sunulmuştur. Ayrıca, (Er+Y)SiAlON camlarının cam geçiş sıcaklıkları artan azot miktarına
göre artış göstermiştir. Bu sonuç (RE+Ca)SiAlON serisiyle kıyaslanmıştır.

Anahtar Kelimeler

Oksinitrür cam, Nadir element etkisi, Azot etkisi, Katyon alan mukavemeti

Kaynakça

• Becher, P.F., Hampshire, S., Pomeroy, J., Hoff- mann, M.J., Lance, M.J. and Satet, R.L. (2011). An Overview of The Structure and Oxynitride Glass, International Journal of Applied Glass Science 2(1), 63-83. Based
• Becher, P.F., Painter, G.S., Sun, E.Y., Hsue, C.H. and Lance, M.J. (2000). The Importance of Amorphous Intergranular Films in Self-Reinforced Si3N4 Ceramics, Acta Materialia 48(18-19), 4493–4499.
• Becher, P.F., Waters, S.B., Westmoreland, C.G. and Riester, L. (2002). Compositional Effects on The Properties of Si - Al – RE - Based Oxynitride Glasses (RE _ La, Nd, Gd, Y, or Lu), Journal of Am. Ceram. Society 85(4), 897-902.
• Hampshire, S. and Pomeroy, M.J. (2004). Effect of Composition on Viscosities of Rare Earth Oxynitride Glasses, Journal of Non-Crystalline Solid 344(1-2), 1-7.
• Hampshire, S. (2008). Developments in Oxynitride Properties Developments in Strategic Materials Ceramic Eng. and Science Proceedings 29(10). ; Crystallization,
• Hampshire, S. (2008). Oxynitride Glasses, Journal of Ceramic Society 28, 1475- 1483.
• Iftekhar, S., Grin, J., Gunawidjaja, P. and Eden, M. (2011). Glass Formation and Structure – Property – Composition Relations of the RE2O3–Al2O3–SiO2 (RE=La, Y, Lu, Sc) Systems, Journal of Am. Ceram. Society, 94 (8), 2429-2435.
• Keyan, L. and Feng, X. (2009). Hardness of Materials: Studies at Levels From Atoms to Crystals, Chinese Science Bulletin.
• Kleebe, H.J., Pezzotti, G., Ziegler, G., Microstructure and Fracture (1999). Toughness of Si3N4 Ceramics: Combined Roles of Grain Morphology and Second- ary Phase Chemistry, Journal of Am. Ceram. Society 82(7), 1857-1867.
• Lofaj, F., Satet, R., Hoffmann, M.J., Lopez, A. and R.A. (2004). Thermal Expansion and Glass Transition Temperature of The Rare-Earth Doped Oxynitride Glasses, Journal of European Ceram. Soc. 24, 3377-3385.
• Menke, Y., Baron, V. and Hampshire, S. (2000). Effect of Rare Earth Cations on Properties of Sialon Glasses, Journal of Non- Crystalline Solids 276, 145-150. Ojovan, M.I. Thermodynamic Symmetry Changes at Glass Transition, Entropy 10, 334-364. Configurons: Parameters and
• Pauling, L. (1932). The Nature of The Chemical Bond. IV. The Energy of Single Bonds and The Relative Electronegativity of Atoms, Journal of the American Chemical Society 54(9), 3570-3582. Effects of Nitrogen on Structure and Properties, Journal of TheCeramicSociety of Japan 116(6), 755-761.
• Pomeroy, J., Nestor, E., Ramesh, R. and Hampshire, S. (2005). Properties and Crystallization of Rare-Earth Si–Al–O–N Glasses Containing Mixed Trivalent Modifiers, Journal of Am. Ceram. Society 88(4), 875-881.
• Ramesh, R., Nestor, E., Pomeroy, J. and Stuart, H. (1997). Formation of La-Si-Al-O-N Glasses And Their Properties, Journal of European Ceram. Soc. 17, 1933-1939.