Structural aspects that enhance oxygen mobility in La9-2x/3Mn0.5 REx▭0.5-x/3(SiO4)6O2 with RE = Ca, Sr and Ba

被引：7

作者：

Inoubli, A. ^{[1
,2
]}

Kahlaoui, M. ^{[1
]}

Chefi, S. ^{[1
]}

Sobrados, I. ^{[3
]}

Madani, A. ^{[1
,4
]}

Sanz, J. ^{[3
]}

Amara, A. Ben Haj ^{[2
]}

机构：

[1] Univ Carthage, Fac Sci Bizerte, Phys Mat Lab, Zarzouna 7021, Tunisia

[2] Univ Carthage, Fac Sci Bizerte, Lab Phys Mat Lamellaires & Nanomat Hybrides, Zarzouna 7021, Tunisia

[3] CSIC, Inst Ciencia Mat, E-28049 Madrid, Spain

[4] Umm Al Qura Univ, Coll Appl Sci, Dept Phys, Mecca, Saudi Arabia

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2014年 / 604卷

关键词：

SOFC; Fuel cells; Ionic conductivity; Impedance spectroscopy; Oxyapatites; Ac conductivities; POWDER NEUTRON-DIFFRACTION; OXIDE-ION CONDUCTION; APATITE-TYPE PHASES; ELECTRICAL-PROPERTIES; LA9.33SI6O26; ELECTROLYTE; RELAXATION;

D O I：

10.1016/j.jallcom.2014.03.140

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Oxyapatite- type silicates, La-9 Mn-2x/3(0.5) REx rectangle 0.5 (x/3)(SiO4)(6)O-2 (x = 0.5; RE = Ca, Sr and Ba), were prepared by a high temperature solid-state reaction. Structure and unit-cell parameters were deduced from the analysis of X-ray powder diffraction data. Le Bail refinement of the X-ray powder diffraction data showed that the compounds have a hexagonal cell (P 63/m space group). The electrical properties of the materials were studied using the ac impedance spectroscopy technique. The extra oxygen O(4) atoms in site 2a (0, 0,0.25) occupy channels running through the structure that are responsible for the high oxygen ion conduction. The presence of cation vacancies should enhance oxygen hopping along the c-axis; however, the analysis of the frequency dependence of ac conductivity suggests that oxygen motions are produced along three axes. The n-factor value of the dimensionality of the oxide ions increases with the conductivity when the size of RE cation decreases. (C) 2014 Elsevier B. V. All rights reserved.

引用

页码：340 / 345

页数：6

共 31 条

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