Enthalpy of formation of rare-earth silicates Y2SiO5 and Yb2SiO5 and N-containing silicate Y10(SiO4)6N2

Jian Jie Liang, Alexandra Navrotsky, Thomas Ludwig, Hans J. Seifert, Fritz Aldinger

Research output: Contribution to journalArticlepeer-review

42 Scopus citations

Abstract

The enthalpies of formation of two rare-earth silicates (Y2SiO5 and Yb2SiO5) and a N-containing rare-earth silicate Y10(SiO4)6N2 have been determined using high-temperature drop solution calorimetry. Alkali borate (52 wt% LiBO2·48 wt% NaBO2) solvent was used at 800°C, and oxygen gas was bubbled through the melt. The nitrogen-containing silicate was oxidized during dissolution. The standard enthalpies of formation are for Y2SiO5, Yb2SiO5, and Y10(SiO4)6N2, respectively, -2868.54 ± 5.34, -2774.75 ± 8.21, and -14145.20 ± 16.48 kJ/mol from elements, and -52.53 ± 4.83, -49.45 ± 8.35, and -94.53 ± 11.66 kJ/mol from oxides (Y2O3 or Yb2O3, SiO2) and nitride (Si3N4). The silicates and N-containing silicate are energetically stable with respect to binary oxides and Si3N4, but the N-containing silicate may be metastable with respect to assemblages containing Y2SiO5, Si3N4, and SiO2. A linear relationship was found between the enthalpy of formation of a series of M2SiO5 silicates from binary oxides and the ionic potential (z/r) of the metal cation.

Original languageEnglish (US)
Pages (from-to)1181-1185
Number of pages5
JournalJournal of Materials Research
Volume14
Issue number4
DOIs
StatePublished - Apr 1999
Externally publishedYes

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint

Dive into the research topics of 'Enthalpy of formation of rare-earth silicates Y<sub>2</sub>SiO<sub>5</sub> and Yb<sub>2</sub>SiO<sub>5</sub> and N-containing silicate Y<sub>10</sub>(SiO<sub>4</sub>)<sub>6</sub>N<sub>2</sub>'. Together they form a unique fingerprint.

Cite this