Electronic structure and thermodynamic stability of LaMnO3 and La1-xSrxMnO3 (001) surfaces: Ab initio calculations.
In: Physical Review B : Condensed matter and materials physics, Vol. 78 (2008), No. 12, 121406(R)
Title:
Electronic structure and thermodynamic stability of LaMnO3 and La1-xSrxMnO3 (001) surfaces: Ab initio calculations.
Author:
Piskunov, Sergej;Heifets, Eugene;Jacob, Timo;Kotomin, Eugene A.;Ellis, Donald E.;Spohr, EckhardUDE
- GND
- 143257005
- LSF ID
- 49123
- ORCID
- 0000-0001-8148-7575
- Other
- connected with university
Year of publication:
2008
Abstract:
We present the results of ab initio hybrid density-functional calculations of the atomic and the electronic structures of LaMnO3 (LMO) and La1-xbSrxbMnO3 (001) surfaces. The total energies obtained from these calculations were used to analyze thermodynamic stability of the surfaces. We predict Sr and O vacancy segregation to the surface to occur with similar energies ( ˜0.5eV per defect). In pure LMO only MnO2 termination is thermodynamically favorable under typical operational conditions of a cathode in solid oxide fuel cells, whereas Sr doping makes La(Sr)O termination favorable. Finally, the role of Sr doping in cathode degradation is discussed.