Cold sintering process of ZnO ceramics: effect of the nanoparticle/microparticle ratio

We show the efficiency in the preparation of 95% dense ZnO ceramics by cold sintering process through the incorporation of ZnO nanoparticles in the 1-10 wt% range at temperatures of 170 degrees C, pressures of 750 MPa and a pellet height/diameter ratio of 0.38. Morphological, structural and physical...

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Bibliographic Details
Authors: Serrano, Aída; Caballero Calero, Olga; García, Miguel Ángel; Lazić, Snežana; Carmona Tejero, Noemí; Castro, German R.; Martín González, Marisol; Fernández, José F.
Format: Article
Publication date:2020
Country:España
Institution:Universidad Complutense de Madrid (UCM)
Repository:Docta Complutense
Language:English
OAI Identifier:oai:docta.ucm.es:20.500.14352/6676
Online Access:https://hdl.handle.net/20.500.14352/6676
Access Level:Open access
Keyword:538.9
Zinc-oxide
Luminescence
Temperature
Nanostructures
Scattering
Vacancies
Oxygen
Física de materiales
Física del estado sólido
2211 Física del Estado Sólido
Description
Summary:We show the efficiency in the preparation of 95% dense ZnO ceramics by cold sintering process through the incorporation of ZnO nanoparticles in the 1-10 wt% range at temperatures of 170 degrees C, pressures of 750 MPa and a pellet height/diameter ratio of 0.38. Morphological, structural and physical properties are dependent on the amount of ZnO nanoparticles incorporated into the system. After the densification by cold sintering process, ZnO ceramics show a reduction of the average valence indicating the deficiency of oxygen, similar to ceramics sintered by the conventional route. Besides, the generation of structural disorder and modifications into the ZnO lattice are identified in sintered ceramics, inducing intrinsic defects related to the loss of oxygen ions, the diffusion of zinc and zinc vacancies, which depend on the sintering process and the starting powders. These characteristics influence the final functional properties of the sintered ZnO ceramics, such as the visible photoluminescence signal.