Glass transition and infrared spectra of low-alkali, anhydrous lithium phosphate glasses

Journal Article · Thu Jul 01 04:00:00 EDT 1993 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1993.tb06636.x· OSTI ID:6349491

Hudgens, J J; Martin, S W ^[1]

---

1. Iowa State Univ. of Science and Technology, Ames, IA (United States). Dept. of Materials Science and Engineering

Anhydrous glasses in the series xLi[sub 2]O + (1 [minus] x)P[sub 2]O[sub 5] have been prepared and characterized in the range 0 [<=] x [<=] 0.5. FT-IR spectroscopy and glass transition temperature measurements have been used to explore the structure and a key physical property of the low-alkali phosphate glasses. The structure of v-P[sub 2]O[sub 5] is proposed to consist of a 3-D network of trigonally connected tetrahedra decorated with a P=O unit. Contrary to what has long been proposed for these glasses, the addition of alkali degrades the 3-D network through the generation of nonbridging oxygens rather than strengthen the network through the proposed alkali ion bridging. The T[sub g] of v-P[sub 2]O[sub 5] is [approximately]653 K and decreases some 130 K with the addition of 10 mol% Li[sub 2]O. T[sub g] then reaches a minimum value at 20 mol% Li[sub 2]O and increases with further Li[sub 2]O additions. The increase in T[sub g], even though the fraction of nonbridging oxygens is still increasing, is interpreted in terms of an increasing entanglement of long-chain PO[sub 2] groups in the glass. Such a structural transition from a 3-D network of interconnected PO[sub 4] groups for P[sub 2]O[sub 5] to a 1-D chain structure for LiPO[sub 3] is one of the first examples of the importance of intermediate-range order in governing the properties of glass.

• OSTI ID: 6349491
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 76:7; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602 -- Other Materials-- Structure &amp; Phase Studies
360606* -- Other Materials-- Physical Properties-- (1992-)
ALKALI METAL COMPOUNDS
CHALCOGENIDES
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
ELEMENTS
GLASS
INFRARED SPECTRA
LITHIUM COMPOUNDS
LITHIUM OXIDES
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHOSPHATE GLASS
PHYSICAL PROPERTIES
SPECTRA
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE