Crystallization kinetics and thermal properties of 20Li{sub 2}O-80TeO{sub 2} glass

Journal Article · Wed Jul 01 04:00:00 EDT 2009 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2009.01.019· OSTI ID:22029815

Idalgo, E ^[1]; Moraes, A P.A.; Filho, A.G. Souza; Filho, J Mendes ^[2]

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1. Universidade Estadual Paulista (UNESP), Departamento de Fisica e Quimica, Caixa Postal 31, 15385-000 Ilha Solteira, SP (Brazil)
2. Universidade Federal do Ceara, Departamento de Fisica, Caixa Postal 6030, 60455-900 Fortaleza, Ce (Brazil)

In this work, X-ray diffraction, Raman spectroscopy and differential scanning calorimetry techniques were used to understand the crystallization process on 20Li{sub 2}O-80TeO{sub 2} glass. X-ray diffraction results reveal the presence of three distinct alpha {gamma}-TeO{sub 2}, {alpha}-TeO{sub 2} and {alpha}-Li{sub 2}Te{sub 2}O{sub 5} crystalline phases in the glass matrix. The Raman spectroscopy band structure of this glass is similar to the one observed in glassy TeO{sub 2}. Raman results clearly reveal the metastable character of the {gamma}-TeO{sub 2} phase in the 20Li{sub 2}O-80TeO{sub 2} glass, whose associated vibration modes disappear completely at temperatures higher than 315 deg. C. On the other hand, the Raman modes associated to {alpha}-TeO{sub 2} and {alpha}-Li{sub 2}Te{sub 2}O{sub 5} phases persists up to temperatures close to the final stages of the crystallization in the studied glass (around 420 deg. C). From DSC measurements, the activation energies 296 {+-} 3 and 298 {+-} 1 kJ mol{sup -1} were associated to {gamma}-TeO{sub 2} and {alpha}-TeO{sub 2} phases crystallization, indicating that these phases crystallizes at temperatures very close in the studied glass.

• OSTI ID: 22029815
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 7 Vol. 44; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
CALORIMETRY
CRYSTALLIZATION
GLASS
OSCILLATION MODES
RAMAN SPECTROSCOPY
TELLURIUM OXIDES
THERMODYNAMIC PROPERTIES
X-RAY DIFFRACTION