Nonstoichiometric Control of Tunnel-Filling Order, Thermal Expansion,   and Dielectric Relaxation in Tetragonal Tungsten Bronzes Ba0.5-xTaO3-x

doi:10.1021/acs.inorgchem.5b01098

CORC > 北京大学 > 化学与分子工程学院

	Nonstoichiometric Control of Tunnel-Filling Order, Thermal Expansion, and Dielectric Relaxation in Tetragonal Tungsten Bronzes Ba0.5-xTaO3-x
	Pan, Fengjuan ; Li, Xiaohui ; Lu, Fengqi ; Wang, Xiaoming ; Cao, Jiang ; Kuang, Xiaojun ; Veron, Emmanuel ; Porcher, Florence ; Suchomel, Matthew R. ; Wang, Jing ; Allix, Mathieu
刊名	INORGANIC CHEMISTRY
	2015
关键词	ELECTRICAL-PROPERTIES POWDER DIFFRACTION CRYSTAL-STRUCTURE PATTERNS SYSTEM M&apos
DOI	10.1021/acs.inorgchem.5b01098
英文摘要	Ordering of interpolated Ba2+ chains and alternate Ta-O rows (TaO)(3+) in the pentagonal tunnels of tetragonal tungsten bronzes (TTB) is controlled by the nonstoichiometry in the highly nonstoichiometric Ba0.5-xTaO3-x system. In Ba0.22TaO2.72, the filling of Ba2+ and (TaO)(3+) groups is partially ordered along the ab-plane of the simple TTB structure, resulting in a root 2-type TTB superstructure (Pbmm), while in Ba0.175TaO2.675, the pentagonal tunnel filling is completely ordered along the b-axis of the simple TTB structure, leading to a triple TTB superstructure (P2(1)2(1)2). Both superstructures show completely empty square tunnels favoring Ba2+ conduction and feature unusual accommodation of Ta5+ cations in the small triangular tunnels. In contrast with stoichiometric Ba6GaTa9O30, which shows linear thermal expansion of the cell parameters and monotonic decrease of permittivity with temperature within 100-800 K, these TTB superstructures and slightly nonstoichiometric simple TTB Ba0.4TaO2.9 display abnormally broad and frequency-dependent extrinsic dielectric relaxations in 10(3)-10(5) Hz above room temperature, a linear deviation of the c-axis thermal expansion around 600 K, and high dielectric permittivity similar to 60-95 at 1 MHz at room temperature.; National Natural Science Foundation of China [21101174, 2151130134]; Guangxi Natural Science Foundation [2014GXNSFGA118004]; Program for New Century Excellent Talents in University [NCET-13-0752]; Guangxi Key Laboratory for Advanced Materials and New Preparation Technology [12AA-11]; U.S. DOE [DE-AC02-06CH11357]; SCI(E); PubMed; ARTICLE; kuangxj@glut.edu.cn; mathieu.allix@cnrs-orleans.fr; 18; 8978-8986; 54
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/416205]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	Pan, Fengjuan,Li, Xiaohui,Lu, Fengqi,et al. Nonstoichiometric Control of Tunnel-Filling Order, Thermal Expansion, and Dielectric Relaxation in Tetragonal Tungsten Bronzes Ba0.5-xTaO3-x[J]. INORGANIC CHEMISTRY,2015.
APA	Pan, Fengjuan.,Li, Xiaohui.,Lu, Fengqi.,Wang, Xiaoming.,Cao, Jiang.,...&Allix, Mathieu.(2015).Nonstoichiometric Control of Tunnel-Filling Order, Thermal Expansion, and Dielectric Relaxation in Tetragonal Tungsten Bronzes Ba0.5-xTaO3-x.INORGANIC CHEMISTRY.
MLA	Pan, Fengjuan,et al."Nonstoichiometric Control of Tunnel-Filling Order, Thermal Expansion, and Dielectric Relaxation in Tetragonal Tungsten Bronzes Ba0.5-xTaO3-x".INORGANIC CHEMISTRY (2015).