Ab initio defect energetics of perovskite (001) surfaces for solid oxide fuel cells: A comparative study of LaMn O3 versus SrTi O3 and LaAl O3

Physical Review B - Condensed Matter and Materials Physics

Volumn 91, Issue 19, 2015, Pages

  Lee, Yueh Lin ^a,b   Morgan, Dane ^a  

^a Wisconsin Electric Machines and Power Electronics Consortium   (United States)

^b Massachusetts Institute of Technology   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 84930221950     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.91.195430     Document Type: Article

References (96)

1. B. C. H. Steele, Survey of materials selection for ceramic fuel cells. 2. Cathodes and anodes, Solid State Ion. 86-88, 1223 (1996). 10.1016/0167-2738(96)00291-3
2. S. B. Adler, Factors governing oxygen reduction in solid oxide fuel cell cathodes, Chem. Rev. 104, 4791 (2004). 10.1021/cr020724o
3. S. C. Singhal and K. Kendall, High Temperature Solid Oxide Fuel Cells: Fundamentals, Design and Applications, 1st ed. (Elsevier Science, Oxford, U.K., 2003).
4. J. A. Kilner, R. A. De Souza, and I. C. Fullarton, Surface exchange of oxygen in mixed conducting perovskite oxides, Solid State Ion. 86-88, 703 (1996). 10.1016/0167-2738(96)00153-1
5. R. A. De Souza and J. A. Kilner, Oxygen transport in (Equation presented) perovskites part II. Oxygen surface exchange, Solid State Ion. 126, 153 (1999). 10.1016/S0167-2738(99)00228-3
6. Y.-L. Lee, J. Kleis, J. Rossmeisl, Y. Shao-Horn and D. Morgan, Prediction of solid oxide fuel cell cathode activity with first-principles descriptors, Energy Environ. Sci. 4, 3966 (2011). 10.1039/c1ee02032c
7. J. H. Kuo, H. U. Anderson, and D. M. Sparlin, Oxidation-reduction behavior of undoped and Sr-doped (Equation presented): Defect structure, electrical conductivity, and thermoelectric power, J. Solid State Chem. 87, 55 (1990). 10.1016/0022-4596(90)90064-5
8. J. Nowotny and M. Rekas, Defect chemistry of (Equation presented), J. Am. Ceram. Soc. 81, 67 (1998). 10.1111/j.1151-2916.1998.tb02297.x
9. J. Fleig, Solid oxide fuel cell cathodes: Polarization mechanisms and modeling of the electrochemical performance, Annu. Rev. Mater. Res. 33, 361 (2003). 10.1146/annurev.matsci.33.022802.093258
10. J. H. Kuo, H. U. Anderson, and D. M. Sparlin, Oxidation-reduction behavior of undoped and sr-doped (Equation presented): Nonstoichiometry and defect structure, J. Solid State Chem. 83, 52 (1989). 10.1016/0022-4596(89)90053-4
11. J. A. M. van Roosmalen and E. H. P. Cordfunke, The defect chemistry of (Equation presented): 5. Thermodynamics, J. Solid State Chem. 110, 113 (1994). 10.1006/jssc.1994.1144
12. F. W. Poulsen, Defect chemistry modelling of oxygen-stoichiometry, vacancy concentrations, and conductivity of (Equation presented), Solid State Ion. 129, 145 (2000). 10.1016/S0167-2738(99)00322-7
13. J. Mizusaki, N. Mori, H. Takai, Y. Yonemura, H. Minamiue, H. Tagawa, M. Dokiya, H. Inaba, K. Naraya, T. Sasamoto and T. Hashimoto, Oxygen nonstoichiometry and defect equilibrium in the perovskite-type oxides (Equation presented), Solid State Ion. 129, 163 (2000). 10.1016/S0167-2738(99)00323-9
14. D. S. Mebane, Y. J. Liu, and M. L. Liu, Refinement of the bulk defect model for (Equation presented), Solid State Ion. 178, 1950 (2008). 10.1016/j.ssi.2008.01.016
15. Y.-L. Lee and D. Morgan, Ab initio and empirical defect modeling of (Equation presented) for solid oxide fuel cell cathodes, Phys. Chem. Chem. Phys. 14, 290 (2012). 10.1039/C1CP22380A
16. P. Decorse, G. Caboche, and L. C. Dufour, A comparative study of the surface and bulk properties of lanthanum-strontium-manganese oxides (Equation presented) as a function of Sr-content, oxygen potential and temperature, Solid State Ion. 117, 161 (1999). 10.1016/S0167-2738(98)00260-4
17. H. Dulli, P. A. Dowben, S.-H. Liou, and E. W. Plummer, Surface segregation and restructuring of colossal-magnetoresistant manganese perovskites (Equation presented), Phys. Rev. B 62, R14629 (R) (2000). 10.1103/PhysRevB.62.R14629
18. Q. H. Wu, M. L. Liu, and W. Jaegermann, X-ray photoelectron spectroscopy of (Equation presented), Mater. Lett. 59, 1480 (2005). 10.1016/j.matlet.2004.12.036
19. N. Caillol, M. Pijolat, and E. Siebert, Investigation of chemisorbed oxygen, surface segregation and effect of post-treatments on (Equation presented) powder and screen-printed layers for solid oxide fuel cell cathodes, Appl. Surf. Sci. 253, 4641 (2007). 10.1016/j.apsusc.2006.10.019
20. T. T. Fister, D. D. Fong, J. A. Eastman, P. M. Baldo, M. J. Highland, P. H. Fuoss, K. R. Balasubramaniam, J. C. Meador, and P. A. Salvador, In situ characterization of strontium surface segregation in epitaxial (Equation presented) thin films as a function of oxygen partial pressure, Appl. Phys. Lett. 93, 151904 (2008). 10.1063/1.2987731
21. G. J. la O', R. F. Savinell, and Y. Shao-Horn, Activity enhancement of dense strontium-doped lanthanum manganite thin films under cathodic polarization: A combined AES and XPS study, J. Electrochem. Soc. 156, B771 (2009). 10.1149/1.3116228
22. K. Katsiev, B. Yildiz, K. Balasubramaniam, and P. A. Salvador, Electron tunneling characteristics on (Equation presented) thin-film surfaces at high temperature, Appl. Phys. Lett. 95, 092106 (2009). 10.1063/1.3204022
23. L. F. J. Piper, A. R. H. Preston, S.-W. Cho, A. DeMasi, B. Chen, J. Laverock, K. E. Smith, L. J. Miara, J. N. Davis, S. N. Basu, U. Pal, S. Gopalan, L. Saraf, T. Kaspar, A. Y. Matsuura, P.-A. Glans, and J.-H. Guo, Soft X-Ray spectroscopic study of dense strontium-doped lanthanum manganite cathodes for solid oxide fuel cell applications, J. Electrochem. Soc. 158, B99 (2011). 10.1149/1.3519075
24. W. Lee, J. W. Han, Y. Chen, Z. Cai, and B. Yildiz, Cation size mismatch and charge interactions drive dopant segregation at the surfaces of manganite perovskites, J. Am. Chem. Soc. 135, 7909 (2013). 10.1021/ja3125349
25. W. A. Harrison, Origin of Sr segregation at (Equation presented) surfaces, Phys. Rev. B 83, 155437 (2011). 10.1103/PhysRevB.83.155437
26. H. Jalili, J. W. Han, Y. Kuru, Z. Cai, and B. Yildiz, New insights into the strain coupling to surface chemistry, electronic structure, and reactivity of (Equation presented), J. Phys. Chem. Lett. 2, 801 (2011). 10.1021/jz200160b
27. B. Puchala, Y.-L. Lee, and D. Morgan, A-Site diffusion in (Equation presented): Ab Initio and kinetic Monte Carlo calculations, J. Electrochem. Soc. 160, F877 (2013). 10.1149/2.077308jes
28. G. J. la O', S.-J. Ahn, E. Crumlin, Y. Orikasa, M. D. Biegalski, H. M. Christen and Y. Shao-Horn, Catalytic activity enhancement for oxygen reduction on epitaxial perovskite thin films for solid-oxide fuel cells, Angew. Chem. Int. Ed. 49, 5344 (2010). 10.1002/anie.201001922
29. E. J. Crumlin, E. Mutoro, Z. Liu, M. E. Grass, M. D. Biegalski, Y.-L. Lee, D. Morgan, H. M. Christen, H. Bluhm, and Y. Shao-Horn, Surface strontium enrichment on highly active perovskites for oxygen electrocatalysis in solid oxide fuel cells, Energy Environ. Sci. 5, 6081 (2012). 10.1039/c2ee03397f
30. M. E. Lynch, L. Yang, W. Qin, J.-J. Choi, M. Liu, K. Blinn and M. Liu, Enhancement of (Equation presented) durability and surface electrocatalytic activity by (Equation presented) investigated using a new test electrode platform, Energy Environ. Sci. 4, 2249 (2011). 10.1039/c1ee01188j
31. D. Oh, D. Gostovic, and E. D. Wachsman, Mechanism of (Equation presented) cathode degradation, J. Mater. Res. 27, 1992 (2012). 10.1557/jmr.2012.222
32. J. Goniakowski, F. Finocchi, and C. Noguera, Polarity of oxide surfaces and nanostructures, Rep. Prog. Phys. 71, 016501 (2008). 10.1088/0034-4885/71/1/016501
33. C. H. Lanier, J. M. Rondinelli, B. Deng, R. Kilaas, K. R. Poeppelmeier, and L. D. Marks, Surface reconstruction with a fractional hole: (Equation presented), Phys. Rev. Lett. 98, 086102 (2007). 10.1103/PhysRevLett.98.086102
34. A. A. Knizhnik, I. M. Iskandarova, A. A. Bagatur'yants, B. V. Potapkin, L. R. C. Fonseca, and A. Korkin, First-principles calculations of the electrical properties of (Equation presented) and its interface with Si, Phys. Rev. B 72, 235329 (2005). 10.1103/PhysRevB.72.235329
35. N. Erdman, K. R. Poeppelmeier, M. Asta, O. Warschkow, D. E. Ellis, and L. D. Marks, The structure and chemistry of the (Equation presented)-rich surface of (Equation presented)(001), Nature 419, 55 (2002). 10.1038/nature01010
36. Y.-L. Lee, J. Kleis, J. Rossmeisl, and D. Morgan, Ab initio energetics of (Equation presented)(001) ((Equation presented), and (Equation presented)) for solid oxide fuel cell cathodes, Phys. Rev. B 80, 224101 (2009). 10.1103/PhysRevB.80.224101
37. Y.-L. Lee and D. Morgan, Prediction of surface oxygen vacancy concentrations of (Equation presented), ECS Trans. 25, 2769 (2009). 10.1149/1.3205838
38. E. A. Kotomin, Y. A. Mastrikov, E. Heifets, and J. Maier, Adsorption of atomic and molecular oxygen on the (Equation presented)(001) surface: Ab initio supercell calculations and thermodynamics, Phys. Chem. Chem. Phys. 10, 4644 (2008). 10.1039/b804378g
39. S. Piskunov, E. Heifets, T. Jacob, E. A. Kotomin, D. E. Ellis, and E. Spohr, Electronic structure and thermodynamic stability of (Equation presented) and (Equation presented) (001) surfaces: Ab initio calculations, Phys. Rev. B 78, 121406 (R) (2008). 10.1103/PhysRevB.78.121406
40. A. Kushima, S. Yip, and B. Yildiz, Competing strain effects in reactivity of (Equation presented) with oxygen, Phys. Rev. B 82, 115435 (2010). 10.1103/PhysRevB.82.115435
41. H. Ding, A. V. Virkar, M. Liu, and F. Liu, Suppression of Sr surface segregation in (Equation presented): A first principles study, Phys. Chem. Chem. Phys. 15, 489 (2013). 10.1039/C2CP43148C
42. Yu. A. Mastrikov, E. Heifets, E. A. Kotomin, and J. Maier, Atomic, electronic and thermodynamic properties of cubic and orthorhombic (Equation presented) surfaces, Surf. Sci. 603, 326 (2009). 10.1016/j.susc.2008.11.034
43. S. Piskunov, T. Jacob, and E. Spohr, Oxygen adsorption at (Equation presented) (001) surfaces: Predictions from first principles, Phys. Rev. B 83, 073402 (2011). 10.1103/PhysRevB.83.073402
44. K. Fuchigami, Z. Gai, T. Z. Ward, L. F. Yin, P. C. Snijders, E. W. Plummer, and J. Shen, Tunable metallicity of the (Equation presented) (001) surface by an oxygen overlayer, Phys. Rev. Lett. 102, 066104 (2009). 10.1103/PhysRevLett.102.066104
45. S. Rößler, B. Padmanabhan, S. Elizabeth, H. L. Bhat, F. Steglich, and S. Wirth, Atomically resolved scanning tunneling microscopy on perovskite manganite single crystals, Appl. Phys. Lett. 96, 202512 (2010). 10.1063/1.3432753
46. B. Bryant, Ch. Renner, Y. Tokunaga, Y. Tokura, and G. Aeppli, Imaging oxygen defects and their motion at a manganite surface, Nat. Commun. 2, 212 (2011). 10.1038/ncomms1219
47. Z. Feng, Y. Yacoby, W. T. Hong, H. Zhou, M. D. Biegalski, H. M. Christen, and Y. Shao-Horn, Revealing the atomic structure and strontium distribution in nanometer-thick (Equation presented)- grown on (001)-oriented (Equation presented), Energy Environ. Sci. 7, 1166 (2014). 10.1039/c3ee43164a
48. J. Suntivich, H. A. Gasteiger, N. Yabuuchi, H. Nakanishi, J. B. Goodenough, and Y. Shao-Horn, Design principles for oxygen-reduction activity on perovskite oxide catalysts for fuel cells and metal-air batteries, Nat. Chem. 3, 546 (2011). 10.1038/nchem.1069
49. J. Suntivich, K. J. May, H. A. Gasteiger, J. B. Goodenough, and Y. Shao-Horn, A Perovskite oxide optimized for oxygen evolution catalysis from molecular orbital principles, Science 334, 1383 (2011). 10.1126/science.1212858
50. I. C. Man, H.-Y. Su, F. Calle-Vallejo, H. A. Hansen, J. I. Martínez, N. G. Inoglu, J. Kitchin, T. F. Jaramillo, J. K. Nørskov, and J. Rossmeisl, Universality in oxygen evolution electrocatalysis on oxide surfaces, ChemCatChem 3, 1159 (2011). 10.1002/cctc.201000397
51. R. A. Evarestov, E. A. Kotomin, D. Fuks, J. Felsteiner, and J. Maier, Ab initio calculations of the (Equation presented) surface properties, Appl. Surf. Sci. 238, 457 (2004). 10.1016/j.apsusc.2004.05.171
52. J. Padilla and D. Vanderbilt, Ab initio study of (Equation presented) surfaces, Surf. Sci. 418, 64 (1998). 10.1016/S0039-6028(98)00670-0
53. J. Carrasco, F. Illas, N. Lopez, E. A. Kotomin, Y. F. Zhukovskii, R. A. Evarestov, Y. A. Mastrikov, S. Piskunov, and J. Maier, First-principles calculations of the atomic and electronic structure of F centers in the bulk and on the (001) surface of (Equation presented), Phys. Rev. B 73, 064106 (2006). 10.1103/PhysRevB.73.064106
54. H. Seo and A. A. Demkov, First-principles study of polar LaAlO (001) surface stabilization by point defects, Phys. Rev. B 84, 045440 (2011). 10.1103/PhysRevB.84.045440
55. E. A. Kotomin, R. A. Evarestov, Yu. A. Mastrikov, and J. Maier, DFT plane wave calculations of the atomic and electronic structure of (Equation presented)(001) surface, Phys. Chem. Chem. Phys. 7, 2346 (2005). 10.1039/b503272e
56. G. Kresse and J. Hafner, Ab initio molecular dynamics for liquid metals, Phys. Rev. B 47, 558 (1993). 10.1103/PhysRevB.47.558
57. G. Kresse and J. Furthmuller, Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set, Phys. Rev. B 54, 11169 (1996). 10.1103/PhysRevB.54.11169
58. P. E. Blochl, Projector augmented-wave method, Phys. Rev. B 50, 17953 (1994). 10.1103/PhysRevB.50.17953
59. G. Kresse and D. Joubert, From ultrasoft pseudopotentials to the projector augmented-wave method, Phys. Rev. B 59, 1758 (1999). 10.1103/PhysRevB.59.1758
60. J. P. Perdew and Y. Wang, Accurate and simple analytic representation of the electron-gas correlation energy, Phys. Rev. B 45, 13244 (1992). 10.1103/PhysRevB.45.13244
61. S. Geller and V. B. Bala, Crystallographic studies of perovskite-like compounds. II. Rare earth alluminates, Acta. Crystallogr. 9, 1019 (1956). 10.1107/S0365110X56002965
62. N. Furuhata, E. Nakamura, and E. Sawaguchi, Landolt-Börnstein, Group III 3 (Springer-Verlag, Berlin, 1969).
63. J. F. Mitchell, D. N. Argyriou, C. D. Potter, D. G. Hinks, J. D. Jorgensen, and S. D. Bader, Structural phase diagram of (Equation presented): Relationship to magnetic and transport properties, Phys. Rev. B 54, 6172 (1996). 10.1103/PhysRevB.54.6172
64. L. Wang, T. Maxisch, and G. Ceder, Oxidation energies of transition metal oxides within the (Equation presented) framework, Phys. Rev. B 73, 195107 (2006). 10.1103/PhysRevB.73.195107
65. F. Calle-Vallejo, J. I. Martínez, J. M. García-Lastra, M. Mogensen, and J. Rossmeisl, Trends in Stability of Perovskite Oxides, Angew. Chem. Int. Ed. 49, 7699 (2010). 10.1002/anie.201002301
66. A. Jain, G. Hautier, C. J. Moore, S. Ping Ong, C. C. Fischer, T. Mueller, K. A. Persson, and G. Ceder, A high-throughput infrastructure for density functional theory calculations, Comput. Mater. Sci. 50, 2295 (2011). 10.1016/j.commatsci.2011.02.023
67. R. F. W. Bader, Atoms in Molecules-a Quantum Theory (Clarendon Press, Oxford, UK, 1994).
68. G. Makov and M. C. Payne, Periodic boundary-conditions in ab-initio calculations, Phys. Rev. B 51, 4014 (1995). 10.1103/PhysRevB.51.4014
69. J. Neugebauer and M. Scheffler, Adsorbate-substrate and adsorbate-adsorbate interactions of Na and K adlayers on Al(111), Phys. Rev. B 46, 16067 (1992). 10.1103/PhysRevB.46.16067
70. K. Tobe, T. Kimura, Y. Okimoto, and Y. Tokura, Anisotropic optical spectra in a detwinned (Equation presented) crystal, Phys. Rev. B 64, 184421 (2001). 10.1103/PhysRevB.64.184421
71. J. Töpfer and J. B. Goodenough, (Equation presented) Revisited, J. Solid State Chem. 130, 117 (1997). 10.1006/jssc.1997.7287
72. X. Luo, B. Wang, and Y. Zheng, First-principles study on energetics of intrinsic point defects in (Equation presented), Phys. Rev. B 80, 104115 (2009). 10.1103/PhysRevB.80.104115
73. T. Tanaka, K. Matsunaga, Y. Ikuhara, and T. Yamamoto, First-principles study on structures and energetics of intrinsic vacancies in (Equation presented), Phys. Rev. B 68, 205213 (2003). 10.1103/PhysRevB.68.205213
74. K. Johnston, M. R. Castell, A. T. Paxton, and M. W. Finnis, (Equation presented)(001)(2 × 1) reconstructions: First-principles calculations of surface energy and atomic structure compared with scanning tunneling microscopy images, Phys. Rev. B 70, 085415 (2004). 10.1103/PhysRevB.70.085415
75. E. Heifets, R. I. Eglitis, E. A. Kotomin, J. Maier, and G. Borstel, First-principles calculations for (Equation presented)(100) surface structure, Surf. Sci. 513, 211 (2002). 10.1016/S0039-6028(02)01730-2
76. J.-L. Tang, J. Zhu, W.-F. Qin, J. Xiong, Y. Zhang, and Y.-R. Li, Atomic relaxation and electronic redistribution of (Equation presented)(001) surfaces, Phys. Lett. A 365, 149 (2007). 10.1016/j.physleta.2006.12.072
77. R. Pentcheva and W. E. Pickett, Avoiding the Polarization Catastrophe in (Equation presented) Overlayers on (Equation presented) (001) through Polar Distortion, Phys. Rev. Lett. 102, 107602 (2009). 10.1103/PhysRevLett.102.107602
78. A. Baldereschi, S. Baroni, and R. Resta, Band offsets in lattice-matched heterojunctions: A model and first-principles calculations for GaAs/AlAs, Phys. Rev. Lett. 61, 734 (1988). 10.1103/PhysRevLett.61.734
79. P. W. Tasker, Stability of ionic-crystal surfaces, J. Phys. C 12, 4977 (1979). 10.1088/0022-3719/12/22/036
80. N. A. Richter, S. Sicolo, S. V. Levchenko, J. Sauer, and M. Scheffler, Concentration of vacancies at metal-oxide surfaces: Case study of MgO(100), Phys. Rev. Lett. 111, 045502 (2013). 10.1103/PhysRevLett.111.045502
81. K. Xiong, J. Robertson, and S. J. Clark, Defect states in the high-dielectric-constant gate oxide (Equation presented). Appl. Phys. Lett. 89, 022907 (2006). 10.1063/1.2221521
82. H. Lu, T. A. George, Y. Wang, I. Ketsman, J. D. Burton, C.-W. Bark, S. Ryu, D. J. Kim, J. Wang, C. Binek, P. A. Dowben, A. Sokolov, C.-B. Eom, E. Y. Tsymbal, and A. Gruverman, Electric modulation of magnetization at the (Equation presented) interfaces, Appl. Phys. Lett. 100, 232904 (2012). 10.1063/1.4726427
83. W. D. Kingery, Plausible Concepts Necessary and Sufficient for Interpretation of Ceramic Grain-Boundary Phenomena: II, Solute Segregation, Grain-Boundary Diffusion, and General Discussion (Equation presented), J. Am. Ceram. Soc. 57, 74 (1974). 10.1111/j.1151-2916.1974.tb10818.x
84. M. F. Yan, R. M. Cannon, and H. K. Bowen, Space charge, elastic field, and dipole contributions to equilibrium solute segregation at interfaces, J. Appl. Phys. 54, 764 (1983). 10.1063/1.332035
85. H. Chen, A. M. Kolpak, and S. Ismail-Beigi, Electronic and magnetic properties of (Equation presented) interfaces from first principles, Adv. Mater. 22, 2881 (2010). 10.1002/adma.200903800
86. N. C. Bristowe, E. Artacho, and P. B. Littlewood, Oxide superlattices with alternating p and n interfaces, Phys. Rev. B 80, 045425 (2009). 10.1103/PhysRevB.80.045425
87. A. Ohtomo and H. Y. Hwang, A high-mobility electron gas at the (Equation presented) heterointerface, Nature 427, 423 (2004). 10.1038/nature02308
88. N. Nakagawa, H. Y. Hwang, and D. A. Muller, Why some interfaces cannot be sharp, Nat. Mater. 5, 204 (2006). 10.1038/nmat1569
89. M. Stengel and D. Vanderbilt, Berry-phase theory of polar discontinuities at oxide-oxide interfaces, Phys. Rev. B 80, 241103 (2009). 10.1103/PhysRevB.80.241103
90. M. Stengel, First-principles modeling of electrostatically doped perovskite systems, Phys. Rev. Lett. 106, 136803 (2011). 10.1103/PhysRevLett.106.136803
91. J. B. Goodenough, Electronic and ionic transport properties and other physical aspects of perovskites, Rep. Prog. Phys. 67, 1915 (2004). 10.1088/0034-4885/67/11/R01
92. J. Rodriguez-Carvajal, M. Hennion, F. Moussa, A. H. Moudden, L. Pinsard, and A. Revcolevschi, Neutron-diffraction study of the Jahn-Teller transition in stoichiometric (Equation presented), Phys. Rev. B 57, R3189 (1998). 10.1103/PhysRevB.57.R3189
93. M. Abbate, F. M. F. Degroot, J. C. Fuggle, A. Fujimori, O. Strebel, F. Lopez, M. Domke, G. Kaindl, G. A. Sawatzky, M. Takano, Y. Takeda, H. Eisaki, and S. Uchida, Controlled-valence properties of (Equation presented) and (Equation presented) studied by soft-x-ray absorption-spectroscopy, Phys. Rev. B 46, 4511 (1992). 10.1103/PhysRevB.46.4511
94. T. Arima, Y. Tokura, and J. B. Torrance, Variation of optical gaps in perovskite-type 3d transition-metal oxides, Phys. Rev. B 48, 17006 (1993). 10.1103/PhysRevB.48.17006
95. H. W. Eng, P. W. Barnes, B. M. Auer, and P. M. Woodward, Investigations of the electronic structure of (Equation presented) transition metal oxides belonging to the perovskite family, J. Solid State Chem. 175, 94 (2003). 10.1016/S0022-4596(03)00289-5
96. V. G. Sathe, S. K. Paranjpe, V. Siruguri, and A. V. Pimpale, Novel magnetic phases in (Equation presented): A neutron diffraction study, J. Phys.: Condens. Matter 10, 4045 (1998). 10.1088/0953-8984/10/18/014