氧化铝掺杂对Ba0.6Sr0.4(Zr0.2Ti0.8)O3陶瓷介电性能的影响

Zr4+取代Ti4+的Ba0.6Sr0.4(Zr0.2Ti0.8)O3固溶体在降低介电常数的同时,保持了BST固溶体优异的可调性。为降低BST材料的介电损耗和介电常数,以氧化铝为改性剂对Ba0.6Sr0.4(Zr0.2Ti0.8)O3材料(BSZT材料)进行了掺杂。随着氧化铝掺杂质量分数从1%到10%增加,BSZT材料的介电常数从5000降低到了1550(100kHz),介电损耗降低到0.001(100kHz)以下,而材料的介电可调性保持在35%左右(1.5kV/mm)。X射线衍射图谱表明,烧结后得到的BSZT材料具有典型的钙钛矿结构。扫描电子显微镜观察表明,氧化铝的掺杂使得陶瓷致密度较高,晶粒均匀。

Dielectric Properties of Ba0.6Sr0.4(Zr0.2Ti0.8)O3 Ceramic Doped with Al2O3

BaxSr1-xTiO3 (BST, 0≤x≤1) is a solid solution ferroelectric material exhibiting a large dielectric constant non-linear change with an applied dc electric field. It has been shown that the dielectric constants and losses of barium strontium titanate can be reduced by doping certain oxides. The Zr4+ ions substitution for Ti4+ ions has a strong effect on decreasing the dielectric constant and keeping dielectric tenability of BST ceramics, which got the BSZT ceramics (Ba0.6Sr0.4(Zr0.2Ti0.8)O3). In this paper, we present systematic studies of the effect of Al3O3 on BSZT bulk ceramics was investigated. When the content of Al2O3 ceramics is increased from 0 wt% to 10 wt% in the BSZT sample, dielectric constant is decreased from 5000 to 1555 (100 kHz) and dielectric losses is under 0.001 (100 kHz), and the relative tunability of BSZT still maintain in 35%. X-ray diffraction analyses indicate that the samples consist of perovskite phase. Scanning electron microscopy micrographs of BST sample indicate the grain size is uniform and the density is increased.