Abstract
The diffusion of radiotracer sulfur in single crystals and in pressed powder compacts of NiO has been studied. The diffusivities for the undoped single crystals were:D = 1.89 × 10-5 exp(-185.3 kJ/RT), cm2/s between 820°C and 1200°C and under virtually constant [0.77 to 1.0 atm] oxygen pressure. The diffusivities in pressed powders were greater than in the corresponding single crystalline specimens. The diffusivity of sulfur in NiO increased as the oxygen partial pressure over the crystal decreased. This result indicates that sulfur might migrate via oxygen vacancies. The diffusivity of sulfur in Cr-doped crystals was found to be about an order of magnitude lower than the undoped crystal. The results obtained on the doped crystals were consistent with the oxygen vacancy mechanism.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
