{"title":"Structural and optical studies of annealed zirconia nanocrystals: Phase transformations, defect dynamics, and magnetic behaviour","authors":"Maneshwar Thakur , Ankush Vij , Akshay Kumar , Bon Heun Koo , Fouran Singh , Vir Singh Rangra","doi":"10.1016/j.ceramint.2024.09.412","DOIUrl":null,"url":null,"abstract":"<div><div>The present study is a continuation of our previous work, where we synthesized and characterized t-ZrO<sub>2</sub> nanocrystals through the combustion method. Further, t-ZrO<sub>2</sub> nanocrystals are annealed at 600, 900, 1200, and 1400°C and characterized through XRD, Raman, FESEM, XPS, photoluminescence (PL), and thermoluminescence (TL) techniques. XRD and Raman patterns reveal that the as-synthesized ZrO<sub>2</sub> nanocrystals exhibit a tetragonal phase, and annealing at different temperatures induces phase transformations. Annealing at 600 °C restores the metastable nature of the tetragonal phase, although monoclinic nucleation is visualized through Raman spectroscopy. Annealing at higher temperatures leads to a complete transformation into the monoclinic phase. FESEM micrographs reveal extensive crystal growth and consolidation upon annealing. XPS analysis shows a reduction in the binding energies of the Zr 3d doublet due to the removal of lattice oxygen and the formation of oxygen vacancies upon annealing. The annealing of the synthesized material at 1400 °C induced a transformation to ferromagnetic behaviour at 300 K, with increased saturation magnetization (Ms) and coercivity (Hc), reflecting the stabilization of magnetic ordering and residual defects in the grain boundary. PL responses confirm the formation of luminescent defects in the crystal lattice. The TL response varies with the crystalline phase, annealing temperature, and radiation dose, suggesting defect creation, migration, and localization in the lattice. Overall, the study provides valuable insights into the structural and optical properties of ZrO<sub>2</sub> nanoparticles annealed at different temperatures.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"50 23","pages":"Pages 50680-50689"},"PeriodicalIF":5.1000,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ceramics International","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S027288422404447X","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}
引用次数: 0
Abstract
The present study is a continuation of our previous work, where we synthesized and characterized t-ZrO2 nanocrystals through the combustion method. Further, t-ZrO2 nanocrystals are annealed at 600, 900, 1200, and 1400°C and characterized through XRD, Raman, FESEM, XPS, photoluminescence (PL), and thermoluminescence (TL) techniques. XRD and Raman patterns reveal that the as-synthesized ZrO2 nanocrystals exhibit a tetragonal phase, and annealing at different temperatures induces phase transformations. Annealing at 600 °C restores the metastable nature of the tetragonal phase, although monoclinic nucleation is visualized through Raman spectroscopy. Annealing at higher temperatures leads to a complete transformation into the monoclinic phase. FESEM micrographs reveal extensive crystal growth and consolidation upon annealing. XPS analysis shows a reduction in the binding energies of the Zr 3d doublet due to the removal of lattice oxygen and the formation of oxygen vacancies upon annealing. The annealing of the synthesized material at 1400 °C induced a transformation to ferromagnetic behaviour at 300 K, with increased saturation magnetization (Ms) and coercivity (Hc), reflecting the stabilization of magnetic ordering and residual defects in the grain boundary. PL responses confirm the formation of luminescent defects in the crystal lattice. The TL response varies with the crystalline phase, annealing temperature, and radiation dose, suggesting defect creation, migration, and localization in the lattice. Overall, the study provides valuable insights into the structural and optical properties of ZrO2 nanoparticles annealed at different temperatures.
期刊介绍:
Ceramics International covers the science of advanced ceramic materials. The journal encourages contributions that demonstrate how an understanding of the basic chemical and physical phenomena may direct materials design and stimulate ideas for new or improved processing techniques, in order to obtain materials with desired structural features and properties.
Ceramics International covers oxide and non-oxide ceramics, functional glasses, glass ceramics, amorphous inorganic non-metallic materials (and their combinations with metal and organic materials), in the form of particulates, dense or porous bodies, thin/thick films and laminated, graded and composite structures. Process related topics such as ceramic-ceramic joints or joining ceramics with dissimilar materials, as well as surface finishing and conditioning are also covered. Besides traditional processing techniques, manufacturing routes of interest include innovative procedures benefiting from externally applied stresses, electromagnetic fields and energetic beams, as well as top-down and self-assembly nanotechnology approaches. In addition, the journal welcomes submissions on bio-inspired and bio-enabled materials designs, experimentally validated multi scale modelling and simulation for materials design, and the use of the most advanced chemical and physical characterization techniques of structure, properties and behaviour.
Technologically relevant low-dimensional systems are a particular focus of Ceramics International. These include 0, 1 and 2-D nanomaterials (also covering CNTs, graphene and related materials, and diamond-like carbons), their nanocomposites, as well as nano-hybrids and hierarchical multifunctional nanostructures that might integrate molecular, biological and electronic components.