本文研究了纳米相和体相多晶样品La 5/6Na 1/6Mn 0.90Fe 0.10O 3的结构、磁性和输运性质.XRD谱图表明两样品都是单相的钙钛矿结构.随着晶粒尺寸的减小晶粒表面处的自旋无序增多,使居里温度降低,同时使自旋相关电子在晶界处的散射增强,提高了材料电阻率.纳米粒子的尺寸效应提高了材料的低场磁电阻;晶粒表面自旋无序的增多使电子在晶粒表面的二阶隧道效应增强,提高了高场磁电阻效应.零场电阻率的拟合结果也表明晶粒尺寸的减小使自旋无序增加.
参考文献
[1] | L Sheng;D Y Xing;D N Sheng et al.[J].Pys Rev Lett,1997,79:1710. |
[2] | X. L. Wang;S. X. Dou;H. K. Liu .Large low-field magnetoresistance over a wide temperature range induced by weak-link grain boundaries in La↓(0.7)Ca↓(0.3)MnO↓(3)[J].Applied physics letters,1998(1/6):396-398. |
[3] | G Q Gong;C Canedy;G Xiao et al.[J].Applied Physics Letters,1995,67:1783. |
[4] | Z Q Li;E Y Jiang;D X Zhang et al.[J].Physics Letters A,2000,277:56. |
[5] | Z Q Li;E Y Jiang;D X Zhang et al.[J].Journal of Magnetism and Magnetic Materials,2001,237:143. |
[6] | S. L. Ye;W. H. Song;J. M. Dai;K. Y. Wang;S. G. Wang;J. J. Du;Y. P. Sun;J. Fang;J. L. Chen;B. J. Gao .Large room-temperature magnetoresistance and phase separation in La_(1-x)Na_(x)MnO_(3) with 0.1≤x≤0.3[J].Journal of Applied Physics,2001(6):2943-2948. |
[7] | Tetsuo Shimura;Toshimasa Hayashi;Yoshiyuki Inaguma et al.[J].Journal of Solid State Chemistry,1996,124:250. |
[8] | T. Tang;S.Y. Zhang;R.S. Huang .Giant magnetoresistance of bulk polycrystalline La_(0.833)Na_(0.167)MnO_3 with Ag_2O addition[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2003(1/2):91-94. |
[9] | S. Megdiche;M. Ellouze;A. Cheikh-Rouhou .Neutron diffraction, structural and magnetic properties of (La_(1-y)Pr_y)_(0.9)Na_(0.1)MnO_3[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2003(1/2):30-37. |
[10] | S Lee;H Y Hwang;Boris I Shraiman et al.[J].Pys Rev Lett,1999,82:4508. |
[11] | J W Cai;C Wang;B G Shen et al.[J].Applied Physics Letters,1997,71:1727. |
[12] | A Gupta;G Q Gong;G Xiao et al.[J].Physical Review B,1996,54:R15629. |
[13] | 曹世勋,秦晓玲,李平林,曹桂新,张金仓,森克德,西村克彦.Er1-xDyxNi2B2C体系中超导和磁性的共存和相互作用[J].低温物理学报,2003(04):241-246. |
[14] | 柴一晟,杨宏顺,刘剑,余旻,曹烈兆.电子型超导体Nd1.85Ce0.15CuO4单晶输运性质研究[J].低温物理学报,2003(04):267-271. |
[15] | 李燕飞,张光宇,桂太龙,王义杰,宋威.La0.7-xCexCa0.3MnO3低场磁电阻的晶格效应[J].低温物理学报,2004(02):126-130. |
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%