采用固相合成法制备出系列Fe掺杂的Bi2Sr2Co2Oy样品,并对样品进行XRD分析,电阻率(ρ)、热电势(S)和顺磁共振研究.结果表明:Fe掺杂浓度x≤0.3时样品基本为单相.Fe掺杂使体系的电阻率略微增大,热电势显著升高,这可能与Fe掺杂降低了空穴载流子浓度有关.Fe掺杂浓度x=0.05样品获得最大的功率因子(power factor,S2/ρ).顺磁共振结果显示,不掺Fe的样品有着较强的顺磁共振(ESR)信号,随着Fe含量的增加,ESR信号向低频方向移动,并逐渐宽化减弱直至消失.这表明Fe掺杂改变了体系的自旋关联状态,占据了Co位参与了Co-O-Co之间的自旋关联.研究结果表明合适的元素掺杂可以有效地调整体系的自旋关联状态,改善材料的热电性能.
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] | Funahashi R;Matsubara I;Ikuta H et al.[J].Japanese Journal of Applied Physics,2000,39:L1127. |
[3] | Li S;Funahashi R;Matsubara I et al.[J].Chemistry of Materials,2000,12:2424. |
[4] | Miyazaki Y;Kudo K;Akoshima M et al.[J].Japanese Journal of Applied Physics,2000,39:531. |
[5] | Gaojie Xu;Ryoji Funahashi;Masahiro Shikano;Ichiro Matsubara;Yuqin Zhou .Thermoelectric properties of the Bi- and Na- substituted Ca_(3)Co_(4)O_(9) system[J].Applied physics letters,2002(20):3760-3762. |
[6] | Masset A C;Michel C;Maignan A et al.[J].Physical Review B,2000,62:166. |
[7] | Funahashi R.;Sodeoka S.;Matsubara I. .Thermoelectric properties of Bi2Sr2Co2Ox polycrystalline materials[J].Applied physics letters,2000(17):2385-2387. |
[8] | Funahashi R;Matsubara I .[J].Applied Physics Letters,2001,79:362. |
[9] | Itoh T.;Terasaki I. .Thermoelectric properties of Bi2.3-xPbxSr2.6Co2Oy single crystals[J].Japanese journal of applied physics,2000(12A):6658-6660. |
[10] | Yamamoto T;Tsukada I;Uchinokura K et al.[J].Japanese Journal of Applied Physics,2000,39:L747. |
[11] | Ando Y.;Segawa K.;Kawata T.;Terasaki I.;Miyamoto N. .Specific-heat evidence for strong electron correlations in the thermoelectric material (Na,Ca) Co2O4[J].Physical Review.B.Condensed Matter,1999(15):10580-10583. |
[12] | Leligny H;Grebille D;Perez O et al.[J].Acta Crystallographica,2000,B56:173. |
[13] | Gaojie Xu;Ryoji Funahashi;Masahiro Shikano;Ichiro Matsubara;Yuqin Zhou .Thermoelectric properties of Bi_(2.2-x)Pb_(x)Sr_(2)Co_(2)O_(y) system[J].Journal of Applied Physics,2002(7):4344-4347. |
[14] | Koshibae W.;Maekawa S.;Tsutsui K. .Thermopower in cobalt oxides[J].Physical Review.B.Condensed Matter,2000(11):6869-6872. |
[15] | Xu Gaojie;Mao Zhiqiang;Yan Hongjie et al.[J].Journal of Physics:Condensed Matter,1998,10:8843. |
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