本工作制备了La0.65(Ca,Ba)0.35Mn1-xFexOy(x=0～0.2)氧化物系列样品.发现在常温附近,含Ba样品的磁阻变化率远比相应含Ca样品的高.在x=0时,样品电阻随温度的变化曲线存在金属-半导体转换峰,随着Fe对Mn的部分替代,该转换峰向低温区移动,当替代量x达到一定程度时,在实验温区观察不到金属-半导体转换峰.磁阻效应在高铁含量时只能在低温观察到.Fe替代Mn对大磁阻效应的影响,可能主要因为:随着Mn3+被Fe3+所替代,样品La0.65(Ca,Ba)0.35Mn1-xFexOy中的铁磁相互作用受到抑制,反铁磁相互作用得到加强.
参考文献
| [1] | Jin S;Tiefel T H;Mccormack M et al.Thousandfold change in resistivity in magnetoresistive La-Ca-Mn-O films[J].Science,1994,264:413-415. |
| [2] | Ju H L;Gopalakrishnan J;Peng J L et al.Dependence of gaint magnetoresistance on oxygen stoichiometry and magnetization in polycrystalline La0.67Ba0.33MnO3[J].Physical Review B,1995,51:6143-6146. |
| [3] | Millis A J;Littlewood P B;Shraiman B I .Double exchange alone does not explain the resistance of La1-xSrxMnO3[J].Physical Review Letters,1995,74:5144-5147. |
| [4] | Helmolt R V;Wecker J;Holzapfel B et al.Giant negative magnetoresistance in peroskite like La2/3Ba1/3MnOx ferromagnetic films[J].Physical Review Letters,1993,71:2331-2333. |
| [5] | Asamitsu A;Moritomo Y;Tomioka Y et al.A structural phase transition induced by an external magnetic field[J].NATURE,1995,373:407-409. |
| [6] | Roder H;Zhang J;Bishop A R .Lattice effects in the colossal magnetoresistance manganites[J].Physical Review Letters,1996,76:1356-1359. |
| [7] | 戴道生;熊光成;吴思诚 .RE1-xTxMnO3氧化物的结构,电磁特性和巨磁电阻[J].物理学进展,1997,17:201-222. |
| [8] | Cai JW;Wang C;Shen BG;Zhao JG;Zhan WS;; .Colossal magnetoresistance of spin-glass perovskite La0.67Ca0.33Mn0.9Fe0.1O3[J].Applied physics letters,1997(12):1727-1729. |
| [9] | Jonker G H .Magnetic compounds with perovskite structure[J].Physica,1956,XXII:702-722. |
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%