Transformation of Eu2O3-doped sepiolite into Mg–Si oxide ceramics at high temperature: phase evolution, microstructural evolution, and photoluminescence properties

AĞIL A. A., Karacaoglu E., Demir B., Koroglu L., Ayas E.

Physica B: Condensed Matter, cilt.735, 2026 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 735
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1016/j.physb.2026.418687
  • Dergi Adı: Physica B: Condensed Matter
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Compendex, INSPEC
  • Anahtar Kelimeler: Enstatite, Eu2O3 inclusion, Forsterite, Photoluminescence, Sepiolite
  • Hakkari Üniversitesi Adresli: Evet

Özet

In this study, the high-temperature phase transformation, microstructural evolution, and optical properties of Eu2O3-doped sepiolite-derived Mg–Si oxide ceramics were investigated. Natural sepiolite powders doped with 1, 2, and 3 mol% Eu2O3 were calcined at 850 °C and sintered at 1200–1300 °C. Thermal analyses (XRF, TG/DTA) revealed structural degradation above 800 °C. XRD results showed that sepiolite transformed into MgSiO3 (enstatite) at 1200 °C, while Mg2SiO4 (forsterite) became dominant at 1300 °C. SEM analysis confirmed the transformation of the original fibrous morphology into dense, irregular grains. Photoluminescence spectra exhibited characteristic Eu3+ emission peaks (5D0→7Fj), with the 5D0→7F2 transition (612 nm) being the most prominent. Increased sintering temperature improved crystallinity, significantly enhancing emission intensity. The results demonstrate that Eu3+-doped magnesium silicate ceramics derived from natural sepiolite are promising, low-cost phosphors for optical applications. This work highlights the transition from natural hydrous silicates to functional ceramic materials with tailored luminescence properties.