Cr3+ chemical diffusivity in aliovalent doped aluminas. Issue 13 (October 2017)

• Record Type: Journal Article
• Authors: Feng, Lin; Dillon, Shen J.
• Is Part Of: Journal of the European Ceramic Society. Volume 37:Issue 13(2017)
• Page Start: 4025
• Page End: 4032
• Publication Date: 2017-10
• Subjects: Diffusion -- Alumina -- Dopant effect; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2017.04.053
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: Average lattice diffusivities of Cr 3+ in undoped, MgO-doped, and SiO2 -doped Al2 O3 have been measured between 1100 and 1300 °C using scanning transmission electron microscopy based x-ray energy dispersive spectroscopy. It has been demonstrated that both MgO and SiO2 dopants have negligible effect on lattice Cr 3+ chemical diffusion. The experimentally determined Arrhenius equations for undoped, MgO-doped, and SiO2 -doped samples are D undoped = 1.9 × 10 − 10 exp ( − 298 k J / mol R T ) m 2 / s, D Mg O = 2.0 × 10 − 13 exp ( − 217 kJ / mol R T ) m 2 / s, and D Si O 2 = 6.2 × 10 − 11 exp ( − 273 kJ / mol R T ) m 2 / s, respectively. The weak dopant effect is discussed in the context of the contributions from both extrinsic point defect concentrations and their cluster binding energies.