doi:10.1016/j.jssc.2022.123525engOrera, AlodiaOliete, Patricia B.Merino, Rosa I.Sanjuán, María LuisaEutectic ceramics of the CeO2 – ZrO2 – MgO system produced by laser-assisted directional solidificationART-2022-130718Oxide 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.2022http://zaguan.unizar.es/record/11992810.1016/j.jssc.2022.123525http://zaguan.unizar.es/record/119928oai:zaguan.unizar.es:119928info:eu-repo/grantAgreement/ES/DGA/T02-20Rinfo:eu-repo/grantAgreement/ES/MCINN/AEI/RYC2018-025553-Iinfo:eu-repo/grantAgreement/ES/MCINN/FEDER/PID2019-107106RB-C32info:eu-repo/grantAgreement/ES/MCINN/FEDER/PID2021-124863OB-I00JOURNAL OF SOLID STATE CHEMISTRY 315 (2022), 123525 [9 pp]by-nc-ndhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/info:eu-repo/semantics/openAccess