Impact of nitrogen and carbon on defect equilibrium in ZrO2
- Resource Type
- Authors
- Hiral D. Tailor; Anderson Janotti; John L. Lyons; Cyrus E. Dreyer; C. G. Van de Walle
- Source
- Acta Materialia. 117:286-292
- Subject
- Materials science
Polymers and Plastics
Inorganic chemistry
Fermi level
Metals and Alloys
chemistry.chemical_element
Charge (physics)
02 engineering and technology
021001 nanoscience & nanotechnology
01 natural sciences
Nitrogen
Oxygen
Electronic, Optical and Magnetic Materials
Hybrid functional
symbols.namesake
chemistry
Impurity
Chemical physics
0103 physical sciences
Ceramics and Composites
symbols
Density functional theory
010306 general physics
0210 nano-technology
Carbon
- Language
- ISSN
- 1359-6454
We investigate the electronic properties of nitrogen and carbon impurities in ZrO2 using density functional theory with a hybrid functional. It is commonly accepted that N substitutes on the O site and is stable in the −1 charge state ( N O − ). The N O − acceptors are then compensated by donor defects such as O vacancies in the +2 charge state. We test the validity of this assumption by determining the formation energies of all relevant charge states of nitrogen and oxygen vacancies as a function of Fermi level. We also examine the effects of carbon, a common unintentional impurity in ZrO2. We find that carbon impurities have relatively low formation energies and would indeed incorporate easily during growth of ZrO2, but they do not affect the equilibrium between nitrogen and oxygen vacancies. Our results show that the Kroger-Vink picture is valid for common growth conditions and the dominant defects are N O − and V O + 2 .