To view this presentation:

  • If you have an MRS account, click the Login button above.
  • New to MRS?  Create a free account here



  0       0

2014 MRS Spring Meeting


L6.08 - Strained Ionic Interfaces: Effect on Oxygen Diffusivity from Atomistic Simulations


Apr 24, 2014 11:15am ‐ Apr 24, 2014 11:30am

Description

The role of materials’ interfaces/grain boundaries on enhancing anion conductivity is a hotly debated issue that has exposed limited understanding on point-defect energetics at interfaces. Using density functional theory (DFT) and interatomic simulations on zirconia, ceria and other related materials, we unravel key interface issues, i.e., oxygen vacancy migration barriers at interfaces in the absence and presence of dopants, and oxygen vacancy-dopant binding energies at interfaces. We show that pure, strained interfaces indeed possess very low oxygen migration barriers; however, the segregated dopants counteract and raise the barriers significantly.

In addition, the dopants bind oxygen vacancies much more strongly at the interfaces than in the bulk, thereby further lowering oxygen diffusivity at interfaces. From DFT calculations, we also show that that strained interfaces could lead to formation of metastable phases that can ultimately dictate unintuitive oxygen vacancy stability. We conclude that the concept of strained interfaces to enhance anion conductivity prevails primarily in the absence of segregated dopants, and strategies that prevent dopant segregation need to be considered in the design of anion-conducting interfacial and nanocrystalline materials.

Speaker(s):

You must be logged in and own this session in order to post comments.

Print Certificate
Review Answers
Print Transcript
Completed on: token-completed_on
Review Answers
Please select the appropriate credit type:
/
test_id: 
credits: 
completed on: 
rendered in: 
* - Indicates answer is required.
token-content

token-speaker-name
token-index
token-content
token-index
token-content
token-index
token-content
token-index
token-content
token-index
token-content
token-index
token-content
/
/
token-index
token-content
token-index
token-content