采用密度泛函离散变分方法计算了Pb掺杂Bi位对[Bi1.68Ca2O4]RS[CoO2]1.69的电子结构和化学键的影响,并讨论了它们与热电性能之间的关系.计算结果表明,掺Pb体系的电子结构表现出半导体特征,与未掺杂的相比,能隙变窄;掺Pb后,在-4.5～1.8 eV的能量范围内,高能态Co 3d与低能态O 2p存在着杂化作用,Pb 6p在费米能级附近的贡献增强.通过计算键级和分子波函数轨道可知,体系的计算键级在ab面和c轴方向表现出各向异性特征,掺Pb后,Co-O、Pb(Bi)-O均比未掺杂体系减弱,而Bi(Pb)-Bi的键性增强.由此推断,掺Pb体系的热电性能将有所改善.
参考文献
| [1] | Terasaki I.;Uchinokura K.;Sasago Y. .LARGE THERMOELECTRIC POWER IN NACO2O4 SINGLE CRYSTALS[J].Physical Review.B.Condensed Matter,1997(20):12685-12687. |
| [2] | Pelloquin D;Hebert S;Maignan A;Raveau B .A new thermoelectric misfit cobaltite: [Sr2CoO3] [CoO2](1.8)[J].Solid state sciences,2004(2):167-172. |
| [3] | Bhattacharya S;Aswal DK;Singh A;Thinaharan C;Kulkarni N;Gupta SK;Yakhmi JV .Anisotropic electrical transport studies of Ca3Co4O9 single crystals grown by the flux method[J].Journal of Crystal Growth,2005(1/4):246-251. |
| [4] | Chou, T.-L.;Chan, T.-S.;Chen, J.-M.;Yamauchi, H.;Karppinen, M..X-ray absorption spectroscopy study of parent misfit-layered cobalt oxide [Sr_2O_2]_qCoO_2[J].Journal of Solid State Chemistry,2013:27-32. |
| [5] | Liu C J;Chen S Y;Shih L J et al.Fabrication of nanotubules of thermoelectric γ-Na0.7 CoO2 using porous aluminum oxide membrane as supporting template[J].Materials Chemistry and Physics,2010,119(03):424. |
| [6] | E. Guilmeau;M. Pollet;D. Grebille;D. Chateigner;B. Vertruyen;R. Cloots;R. Funahashi;B. Ouladiaff .Neutron diffraction texture analysis and thermoelectric properties of BiCaCoO misfit compounds[J].Materials Research Bulletin: An International Journal Reporting Research on Crystal Growth and Materials Preparation and Characterization,2008(2):394-400. |
| [7] | Itahara H;Xia C;Sugiyama J et al.Fabrication of textured thermoelectric layered cobaltites with various rock salt-type layers by using β-Co (OH)2 platelets as reactive templates[J].Journal of Materials Chemistry,2004,14(01):61. |
| [8] | Matsubara I.;Takeuchi T.;Sodeoka S.;Funahashi R. .Thermoelectric properties of spark plasma sintered Ca2.75Gd0.25Co4O9 ceramics[J].Journal of Applied Physics,2001(1):462-465. |
| [9] | Yuqin Zhou;Ichiro Matsubara;Shigeru Horii;Tomonari Takeuchi;Ryoji Funahashi;Masahiro Shikano;Jun-ichi Shimoyama;Kohji Kishio;Woosuck Shin;Noriya Izu;Norimitsu Murayama .Thermoelectric properties of highly grain-aligned and densified Co-based oxide ceramics[J].Journal of Applied Physics,2003(5):2653-2658. |
| [10] | B. Rivas-Murias;H. Muguerra;M. Traianidis;C. Henrist;B. Vertruyen;R. Cloots .Enhancement of the power factor of [Bi_(1.68)Ca_2O_4]~(RS)[CoO_2]_(1.69)- Ag composites prepared by the spray-drying method[J].Solid state sciences,2010(8):1490-1495. |
| [11] | A. Sotelo;Sh. Rasekh;M.A. Madre .Solution-based synthesis routes to thermoelectric Bi_2Ca_2Co_(1.7)O_x[J].Journal of the European Ceramic Society,2011(9):1763-1769. |
| [12] | Maignan A.;Hebert S.;Hervieu M.;Michel C.;Pelloquin D.;Khomskii D. .Magnetoresistance and magnetothermopower properties of Bi/Ca/Co/O and Bi(Pb)/Ca/Co/O misfit layer cobaltites[J].Journal of Physics. Condensed Matter,2003(17):2711-2723. |
| [13] | Singh D J .Electronic structure of NaCo2O4[J].Physical Review B:Condensed Matter,2000,61(20):13397. |
| [14] | Prevel M;Perez O;Noudem J G .Bulk textured Ca2.5-(RE)0.5Co4O9(RE:Pr,Nd,Eu,Dy and Yb) thermoelectric oxides by sinter-forging[J].Solid State Sciences,2007,9(3-4):231. |
| [15] | F. Delorme;C. Fernandez Martin;P. Marudhachalam .Effect of Ca substitution by Sr on the thermoelectric properties of Ca_3Co_4O_9 ceramics[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2011(5):2311-2315. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%