Eutectic ceramics of the CeO2 – ZrO2 – MgO system produced by laser-assisted directional solidification

Orera, Alodia (Universidad de Zaragoza) ; Oliete, Patricia B. (Universidad de Zaragoza) ; Merino, Rosa I. ; Sanjuán, María Luisa

Resumen: Oxide eutectics have great potentiality as structural or functional materials, owing to the outstanding properties derived from the eutectic microstructure. Among them, the eutectic of the ZrO2 – MgO system is particularly noteworthy because of the unusual combination of thermomechanical, optical and electrical properties. In a recent application, Zr1-δMgδO2-δ – MgO eutectic oxides have been used to produce porous supports for molten-carbonate based CO2 separation membranes. Here we explore composite ceramic oxides of the CexZr1-xO2 – MgO (x ​≤ ​0.5) system with eutectic microstructure, with the motivation that incorporating cerium may enhance the CO2 permeation properties. Eutectic composites with different cerium content are produced by a laser-assisted directional solidification technique at variable solidification rate, v. In all cases the composite bicrystal consists of two phases, MgO and a fluorite-like (CexZr1-x)1-yMgyO2-y phase. A purely fibrilar microstructure is found for x ​≥ ​0.3 ​at v ​= ​25 ​mm/h, with MgO fibres embedded within the fluorite-like matrix. The MgO mol% in the eutectic composites decreases from ∼53% for x ​= ​0 to ∼48% for x ​= ​0.5. X-ray and Raman results evidence long-range ordering in a quasi-tetragonal monoclinic symmetry for x ​= ​0.5. Impedance spectroscopy results are consistent with a change from ionic to mainly electronic conductivity when the atmosphere is changed from air or Ar to 5%H2–Ar.

Idioma: Inglés

DOI: 10.1016/j.jssc.2022.123525

Año: 2022

Publicado en: JOURNAL OF SOLID STATE CHEMISTRY 315 (2022), 123525 [9 pp]
ISSN: 0022-4596

Factor impacto JCR: 3.3 (2022)

Categ. JCR: CHEMISTRY, INORGANIC & NUCLEAR rank: 13 / 42 = 0.31 (2022) - Q2 - T1
Categ. JCR: CHEMISTRY, PHYSICAL rank: 88 / 161 = 0.547 (2022) - Q3 - T2

Factor impacto CITESCORE: 5.6 - Materials Science (Q2) - Chemistry (Q2) - Physics and Astronomy (Q1)

Factor impacto SCIMAGO: 0.58 - Ceramics and Composites (Q2) - Condensed Matter Physics (Q2) - Physical and Theoretical Chemistry (Q2) - Inorganic Chemistry (Q2) - Materials Chemistry (Q2) - Electronic, Optical and Magnetic Materials (Q2)

Financiación: info:eu-repo/grantAgreement/ES/DGA/T02-20R
Financiación: info:eu-repo/grantAgreement/ES/MCINN/AEI/RYC2018-025553-I
Financiación: info:eu-repo/grantAgreement/ES/MCINN/FEDER/PID2019-107106RB-C32
Financiación: info:eu-repo/grantAgreement/ES/MCINN/FEDER/PID2021-124863OB-I00

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Cienc.Mater. Ingen.Metal. (Dpto. Ciencia Tecnol.Mater.Fl.)