采用短时固相反应和放电等离子烧结(SR-SPS)方法, 制备了单相多晶Ca3Co2O6陶瓷块, 系统研究了制备条件及烧结工艺对Ca3Co2O6陶瓷块显微结构及热电性能的影响. 研究表明, 950 ℃下固相反应2 h即能得到单相树枝状, 尺寸约1~3 μm的Ca3Co2O6粉末, 延长焙烧时间虽然对物相影响不大, 但会引起粉末颗粒长大, 不利于SPS烧结;SPS烧结温度强烈影响着Ca3Co2O6陶瓷块的制备, 本实验范围内, Ca3Co2O6陶瓷块体的最佳制备条件为950 ℃固相反应2 h, SPS 900 ℃保温5 min, 此时Ca3Co2O6陶瓷块具有p型半导体特性, 电阻率ρ随温度的升高急剧下降, 然后趋于平缓(高于600 ℃);Seebeck系数S随温度(100 ℃以上)升高稍有下降, 热导率κ表现为先下降后增加, 在500 ℃时仅为1.73 W·m-1·K-1. 综合电性能与热性能结果, 其无量纲因子ZT随温度升高呈上升趋势, 在本实验范围内, 于700 ℃下达到最高值0.02.
参考文献
[1] | Sales B C;Mandrus D;Williams R K .Filled Skutterudite antimonides:A new class of thermoelectric materials[J].Science,1996,272:1325. |
[2] | Nolas GS.;Slack GA.;Cohn JL. .Effect of partial void filling on the lattice thermal conductivity of skudderudites[J].Physical Review.B.Condensed Matter,1998(1):164-170. |
[3] | Terasaki I.;Uchinokura K.;Sasago Y. .LARGE THERMOELECTRIC POWER IN NACO2O4 SINGLE CRYSTALS[J].Physical Review.B.Condensed Matter,1997(20):12685-12687. |
[4] | Funahashi R.;Ikuta H.;Takeuchi T.;Mizutani U.;Sodeoka S.;Matsubara I. .An oxide single crystal with high thermoelectric performance in air[J].Japanese journal of applied physics,2000(11B):L1127-L1129. |
[5] | Tsubota T.;Eguchi K.;Arai H.;Ohtaki M. .Transport properties and thermoelectric performance of (Zn1-yMgy)(1-x)AlxO[J].Journal of Materials Chemistry: An Interdisciplinary Journal dealing with Synthesis, Structures, Properties and Applications of Materials, Particulary Those Associated with Advanced Technology,1998(2):409-412. |
[6] | Li S W;Funahashi R;Matsubara I et al.High temperature thermoelectric properties of oxide Ca9Co12O28[J].Journal of Materials Chemistry,1999,9:1659. |
[7] | Masset A C;Michel D;Maignan A et al.Misfit-layered cobaltite with an anisotropic giant magnetoresistance:Ca3Co4O9[J].Physical Review B,2000,62(01):166. |
[8] | Matsubara I;Funahashi R;Takeuchi T .Thermoelectric properties of spark plasma sintered Ca2.75Ga0.25Co4O9[J].Journal of Applied Physiology,2001,90(01):462. |
[9] | Raquet B;Baibich M N;Broto J M et al.Hopping conductivity in one-demensional Ca3Co2O6 single crystals[J].Physical Review B,2002,65:104442. |
[10] | M. Mikami;R. Funahashi;M. Yoshimura;Y. Mori;T. Sasaki .High-temperature thermoelectric properties of single-crystal Ca_(3)Co_(2)O_(6)[J].Journal of Applied Physics,2003(10):6579-6582. |
[11] | Fjellvag H;Gulbrandsen E;Aasland S et al.Crystal structure and possible change ordering in one-demensional Ca3Co2O6[J].Journal of Solid State Chemistry,1996,124:190. |
[12] | Li S W;Funahashi R;Matsubara I .Synthesis and thermoelectric properties of the new oxide materials Ca3-xBixCo4O9[J].Chemistry of Materials,2000,12:2424. |
[13] | Nan J;Wu J;Deng Y.Synthesis and thermoelectric properties of (NaxCa1-x)3Co4O9 ceramics[J].Journal of the European Ceramic Society,2000 |
[14] | Lotgering F K .Topotactical reactions with ferrimagnetic oxides having hexagonal crystal structure[J].Journal of Radioanalytical and Nuclear Chemistry,1959,9:113. |
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%