摘要
通过X射线衍射(XRD)、拉曼光谱(RS)、扫描电子显微镜(SEM)、电子顺磁共振(EPR)和介电测试技术研究了Ce和Ca共掺杂BaTiO_3陶瓷的结构、价态、位占据和介电性质。Ba/Ti比例有效的影响了陶瓷的结构。所有陶瓷样品中Ce离子不能以Ce^(4+)完全并入Ti位,或以Ce^(3+)完全并入Ba位。当Ba/Ti=1,(Ba_(1-x)Ca_x)(Ti_(0.95)Ce_(0.05))O_3(x=0.05)陶瓷形成单相四方结构,具有Ba位(Ca^(2+)/Ce^(3+))和Ti位(Ca^(2+)/Ce^(4+))混合价态的双位占据,缺陷复合体Ca^(2+)-Ce^(4+)形成。CeCa_5A(Ba/Ti=0.937)陶瓷为单相立方结构,展现一级相变的介电行为,室温附近具有非常高的介电常数(ε′=16000)。
The structure, valence states, site occupations and dielectric properties of Ce and Ca co-doped BaTiO3ceramics were studied using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM),electron paramagnetic resonance (EPR) and dielectric measurements. The Ba/Ti ratio has effects on ceramic structure.Ce ions in all samples cannot incorporate completely into Ti sites as Ce4+ or occupy Ba sites completely as Ce3+. WhenBa/Ti=l, the nominal (Bal_xCax)(Ti0.95Ce0.05)O3 (x=0.05) ceramic has a single-phase tetragonal perovskite structure,with the site occupations of mixed Ca2+/Ce3+ at Ba sites and Ca2+/Ce4+ at Ti sites, and the formation of Ca2+-Ce4+defect complexes. CeCasA (Ba/Ti=0.937) ceramic has a single-phase cubic structure, and shows a first-order phasetransition (FPT) dielectric behavior and a very high dielectric constant (ε =16000) near room temperature.
作者
王长昊
王辰
韩丹丹
WANG Changhao WANG Chen HAN Dandan(School of Science, Jilin Institute of Chemical Technology, Jilin 132022, China School of Materials Science and Engineering Jilin Institute of Chemical Technology, Jilin 132022, China)
出处
《中国陶瓷》
CSCD
北大核心
2017年第7期31-35,共5页
China Ceramics
基金
吉林省教育厅项目(2015435)