当前位置: X-MOL 学术Mater. Sci. Eng. B › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Role of charge compensation mechanism on phase formation, dielectric and ferroelectric properties in aliovalent Gd3+ ion modified PbMg1/3Nb2/3O3 ceramics
Materials Science and Engineering: B ( IF 3.9 ) Pub Date : 2020-01-22 , DOI: 10.1016/j.mseb.2020.114495
Adityanarayan H. Pandey , Surya Mohan Gupta

Phase, microstructural, dielectric and ferroelectric properties investigation clearly reveal that the charge imbalance created due to alio-valent Gd3+-ion substitution at the Pb2+-site in lead magnesium niobate (PMN) should be compensated by changing the B-site cation ratio instead of creating the A-site or B-site vacancies. Microstructure analysis along with elemental mapping exhibit segregation of MgO and GdNbO4 phase, which is consistent with the Gd3+-ions solubility limit in the PMN. Gd3+-ion substituted PMN (PGMN) where the charge imbalance is compensated by creating the A-site vacancies leads to formation of large concentration of pyrochlore phase. Fitting of frequency dependent temperature of dielectric constant maximum [Tm(f)] and the Mydosh parameter “K” calculated from the Tm(f) clearly reveals critical slowing down of polar nano-regions (PNRs) dynamics leading to a super-dipolar glass state in PGMN in which the charge imbalance is compensated by changing the B-site cations ratio or by creating the B-site vacancy.



中文翻译:

电荷补偿机制对异价Gd 3+离子改性PbMg 1/3 Nb 2/3 O 3陶瓷的相形成,介电和铁电性能的作用

相,微结构,介电和铁电特性研究清楚地表明,由于铌酸铅镁(PMN)的Pb 2+位上的异价Gd 3+离子取代而产生的电荷失衡应通过改变B位来补偿阳离子比率而不是创建A站点或B站点空缺。微观结构分析和元素映射显示MgO和GdNbO 4相偏析,这与PMN中Gd 3+离子的溶解度极限一致。Gd 3+离子取代的PMN(PGMN),通过创建A-位空位来补偿电荷不平衡,从而导致形成大量的烧绿石相。拟合频率随温度变化的介电常数最大值[ T mf)]和从T mf)计算出的Mydosh参数“ K ”,清楚地揭示了极性纳米区(PNRs)动力学的严重减慢,从而导致了超导PGMN中的双极玻璃态,其中电荷不平衡通过改变B位阳离子比率或通过产生B位空位来补偿。

更新日期:2020-01-22
down
wechat
bug