Electrical Conductivity and Phase Transition of Solid Oxide Fuel Cell Electrolyte La2Mo2-xTixO9-δ Ceramics

2012 ◽  
Vol 557-559 ◽  
pp. 1223-1227
Author(s):  
Ju Mei Yu ◽  
Ming Ju Chao ◽  
De Chuan Li ◽  
Ming Yu Li ◽  
Hua Wu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Solid State Reaction Method ◽  
Pure Oxygen ◽  
Transport Numbers ◽  
Structure Transition ◽  
Ion Conductor ◽  
Oxygen Ion ◽  
Oxygen Ion Conductor ◽  
Electrical Conductivities ◽  
Ion Transport Numbers

A novel series of ceramic samples La2Mo2-xTixO9-δ (x = 0, 0.025, 0.05, 0.075) were prepared by solid-state reaction method. Their structures and phase transitions were studied by XRD, DSC and CTE. Their Electrical conductivities and oxygen ion transport numbers were measured by AC impedance spectroscopy at 773~1073 K and EMF at 673~1073 K, respectively. Results showed that even when x=0.075, the sample was almost pure oxygen ion conductor under the oxygen partial pressure gradient of 1.0 atm/0.21 atm, and though all the Ti-doped samples still underwent α/β structure transition, no abrupt change in the electrical conductivity was observed accompanying with the transition. They exhibited considerably higher electrical conductivity than La2Mo2O9, especially at 773~873 K and the conductivity increased with increasing x value. The value of conductivity for La2Mo1.925Ti0.075O9-δ reached 8.5×10-3 S•cm-1 at 773 K and 0.08 S•cm-1 at 1,073 K.

Microstructure and Property Study of La2Mo1.5W0.5O9/Ag Composites

2010 ◽  
Vol 663-665 ◽  
pp. 620-624
Author(s):  
Chun Li ◽  
Da Li ◽  
Qian Feng Fang
Keyword(s):  
Solid State Reaction Method ◽  
Second Phase ◽  
Doping Amount ◽  
Conventional Solid State Reaction ◽  
Single Phase Sample ◽  
Ion Conductor ◽  
Oxygen Ion ◽  
Direct Current Conductivity ◽  
Oxygen Ion Conductor ◽  
Sample Density

Based on the oxygen ion conductor La2Mo1.5W0.5O9, a series of Ag2O doped samples La2Mo1.5W0.5O9/Ag were prepared with conventional solid-state reaction method. The effects of Ag2O doping on the microstructure and electrical conductivity have been investigated by XRD, FESEM and direct current conductivity measurements. With the increase of Ag2O doping, the grain was further refined and compacted, meanwhile, Ag diffusion distribution in the form of second-phase appear at grain boundary. The sample density and conductivity also gradually increased with the increasing of doping amount. The conductivity of the composite specimen La2Mo1.5W0.5O9 /Ag has a great enhancement when the concentration of Ag2O is around 27 wt%, which is eight times higher than that of the single-phase sample.

Activity of Bi2O3 in Bi2O3Y2O3 oxygen ion conductor

1992 ◽  
Vol 98 (1) ◽  
pp. 206-209 ◽  
Author(s):  
Keqin Huang ◽  
Changzhen Wang ◽  
Xiuguang Xu
Keyword(s):  
Ion Conductor ◽  
Oxygen Ion ◽  
Oxygen Ion Conductor

A Composite Ionic-Electronic Conductor in the (Ca,Sr,Ba)-Bi Oxide System

2000 ◽  
Vol 658 ◽  
Author(s):  
James K. Meen ◽  
Oya A. Gökçen ◽  
I-C. Lin ◽  
Karoline Müller ◽  
Binh Nguyen
Keyword(s):  
Polymorphic Transformation ◽  
Alkaline Earth ◽  
Binary Systems ◽  
Bulk Composition ◽  
Stability Limit ◽  
Rhombohedral Phase ◽  
Ion Conductor ◽  
Electronic Conductor ◽  
Oxygen Ion ◽  
Oxygen Ion Conductor

ABSTRACTThe rhombohedral alkaline earth-bismuth oxide phase, an oxygen ion conductor, does not coexist stably with electronic conductors in any of the three binary systems, Ca-Bi-O, Sr-Bi-O, Ba-Bi-O. A thermodynamically stable composite of a rhombohedral phase that contains Ba and Sr or Ca or both with the electronic conductor BaBiO3 may be synthesized. The rhombohedral phase appears to have complete mutual miscibility of the alkaline earth elements. The composi- tions of rhombohedral phase that coexist with BaBiO3 in the Sr-Ba-Bi ternary system and the Ca- Sr-Ba-Bi quaternary systems are described. The value of ionic conductivity of the rhombohedral phase (at a constant Bi: [Ca+Sr+Ba]) is not dependent on the relative amounts of Ca, Sr, and Ba. The temperature at which the rhombohedral phase undergoes a polymorphic transformation from a low-temperature (2) form that is a weak ion conductor to a high-temperature (β1) form that is a much better oxygen ion conductor. The temperatures of the polymorphic transformation and of the upper stability limit of the rhombohedral phase both depend strongly on Ca: Sr: Ba. The β1 form develops in the Ba-Bi system at the lowest temperatures and at the highest ones in the Ca- Bi system. On the other hand, the Ca-Bi phase has greater thermal stability than its Ba ana- logues. The temperature range over which a useful composite conductor can operate is, there- fore, strongly dependent upon the bulk composition of the system.

Evidence for the dynamic relaxation behavior of oxygen vacancies in Aurivillius Bi2MoO6 from dielectric spectroscopy during resistance switching

2019 ◽  
Vol 7 (29) ◽  
pp. 8915-8922 ◽  
Author(s):  
Fei Guo ◽  
Mengting Zhao ◽  
Kang Xu ◽  
Yu Huan ◽  
Shuaipeng Ge ◽  
...  
Keyword(s):  
Resistive Switching ◽  
Dielectric Spectroscopy ◽  
Oxygen Vacancies ◽  
Relaxation Behavior ◽  
Switching Behavior ◽  
Dynamic Relaxation ◽  
Resistive Switching Behavior ◽  
Ion Conductor ◽  
Oxygen Ion ◽  
Oxygen Ion Conductor

The resistive switching behavior of oxygen ion conductor Bi2MoO6 were investigated by dielectric spectroscopy.

Dopant Substitution and Ion Migration in the LaGaO3-Based Oxygen Ion Conductor

1998 ◽  
Vol 102 (17) ◽  
pp. 3099-3104 ◽  
Author(s):  
M. S. Khan ◽  
M. S. Islam ◽  
D. R. Bates
Keyword(s):  
Ion Migration ◽  
Ion Conductor ◽  
Oxygen Ion ◽  
Oxygen Ion Conductor
Sign in / Sign up

Export Citation Format

Share Document