{"title":"Enhanced room-temperature ferromagnetism and tuned band gap in AlCoO3-modified lead-free Bi0.5Na0.5TiO3","authors":"Nguyen Huu Lam, Dang Duc Dung","doi":"10.1007/s10971-025-06690-z","DOIUrl":null,"url":null,"abstract":"<div><p>Lead-free Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub> modified with AlCoO<sub>3</sub> was synthesized via a chemical method. The effects of AlCoO<sub>3</sub> incorporation on the crystal structure, optical properties, and magnetic behavior of Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub> were systematically investigated. The incorporation of Al and Co cations into the Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub> lattice during solid-solution formation induced lattice distortions. In addition, a significant reduction in the optical band gap energy, from 3.07 eV for pure Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub> to 2.24 eV for Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub> containing 9 mol.% AlCoO<sub>3</sub> was also observed. Furthermore, magnetic measurements revealed that pure Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub> exhibited weak ferromagnetism with prominent diamagnetic contributions at room temperature. With increasing AlCoO<sub>3</sub> concentration, the magnetic response transitioned to typical ferromagnetism. At higher AlCoO<sub>3</sub> concentrations, the magnetic behavior became more complex, displaying a combination of ferromagnetic, paramagnetic, and/or antiferromagnetic-like characteristics. These results demonstrate the successful integration of magnetic functionalities into lead-free ferroelectric materials, offering new possibilities for their use in multifunctional applications.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":"114 2","pages":"571 - 580"},"PeriodicalIF":2.3000,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Sol-Gel Science and Technology","FirstCategoryId":"88","ListUrlMain":"https://link.springer.com/article/10.1007/s10971-025-06690-z","RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}
引用次数: 0
Abstract
Lead-free Bi0.5Na0.5TiO3 modified with AlCoO3 was synthesized via a chemical method. The effects of AlCoO3 incorporation on the crystal structure, optical properties, and magnetic behavior of Bi0.5Na0.5TiO3 were systematically investigated. The incorporation of Al and Co cations into the Bi0.5Na0.5TiO3 lattice during solid-solution formation induced lattice distortions. In addition, a significant reduction in the optical band gap energy, from 3.07 eV for pure Bi0.5Na0.5TiO3 to 2.24 eV for Bi0.5Na0.5TiO3 containing 9 mol.% AlCoO3 was also observed. Furthermore, magnetic measurements revealed that pure Bi0.5Na0.5TiO3 exhibited weak ferromagnetism with prominent diamagnetic contributions at room temperature. With increasing AlCoO3 concentration, the magnetic response transitioned to typical ferromagnetism. At higher AlCoO3 concentrations, the magnetic behavior became more complex, displaying a combination of ferromagnetic, paramagnetic, and/or antiferromagnetic-like characteristics. These results demonstrate the successful integration of magnetic functionalities into lead-free ferroelectric materials, offering new possibilities for their use in multifunctional applications.
期刊介绍:
The primary objective of the Journal of Sol-Gel Science and Technology (JSST), the official journal of the International Sol-Gel Society, is to provide an international forum for the dissemination of scientific, technological, and general knowledge about materials processed by chemical nanotechnologies known as the "sol-gel" process. The materials of interest include gels, gel-derived glasses, ceramics in form of nano- and micro-powders, bulk, fibres, thin films and coatings as well as more recent materials such as hybrid organic-inorganic materials and composites. Such materials exhibit a wide range of optical, electronic, magnetic, chemical, environmental, and biomedical properties and functionalities. Methods for producing sol-gel-derived materials and the industrial uses of these materials are also of great interest.