通过溶胶-凝胶法,合成了稀土Dy3+掺杂的Fe3O4样品,研究了掺杂对电磁性质的影响.通过X射线衍射分析发现,由于离子半径的不匹配,Fe3O4中稀土离子的高浓度掺杂不能实现,仅有极少量的稀土离子取代了Fe3O4中的Fe3+.通过振动样品磁强计对磁性质进行了表征,掺杂引起样品饱和磁化强度发生变化,这可能是因为Dy3+取代引起的磁化强度增加和杂相引起的磁化强度降低共同作用的结果.四电极法研究隧道磁阻发现,磁阻与掺杂量的关系表现出降低-升高-降低的特殊变化规律.这主要是由于掺杂Fe3O4自旋极化率降低导致隧穿磁阻下降,同时,掺杂Fe3O4在隧穿颗粒体系中实现了第二相即绝缘相的同步合成,第二相的出现有利于隧穿磁阻的增加.
参考文献
[1] | Lewis SP.;Sasaki T.;Allen PB. .BAND STRUCTURE AND TRANSPORT PROPERTIES OF CRO2[J].Physical Review.B.Condensed Matter,1997(16):10253-10260. |
[2] | Korotin MA.;Khomskii DI.;Sawatzky GA.;Anisimov VI. .CrO2: A self-doped double exchange ferromagnet[J].Physical review letters,1998(19):4305-4308. |
[3] | Kobayashi K L;Kimura T;Sawada H et al.Room-temperature magnetoresistance in an oxide material with an ordered double-perovskite structure[J].Nature,1998,395:677. |
[4] | Nadgorny B.;Osofsky M.;Soulen RJ.;Broussard P.;Stroud RM. Singh DJ.;Harris VG.;Arsenov A.;Mukovskii Y.;Mazin II. .Origin of high transport spin polarization in La0.7Sr0.3MnO3: Direct evidence for minority spin states - art. no. 184433[J].Physical Review.B.Condensed Matter,2001(18):184433_1-184433_5. |
[5] | Penicaud M;Siberchicot B;Sommers C B et al.Calculated electronic band-structure and magnetic-moments of ferrites[J].Journal of Magnetism and Magnetic Materials,1992,103:212. |
[6] | Coey JMD.;Balcells L.;Putris FF.;Parker FT.;Berkowitz AE. .Magnetoresistance of magnetite[J].Applied physics letters,1998(6):734-736. |
[7] | Tang JK.;Zhou WL.;Wang KY. .Magnetic properties of nanocrystalline Fe3O4 films[J].Journal of Applied Physics,2001(11 Pt.2):7690-7692. |
[8] | Manoharan SS.;Reiss G.;Goodenough JB.;Elefant D. .Extrinsic giant magnetoresistance in chromium (IV) oxide, CrO2[J].Applied physics letters,1998(8):984-986. |
[9] | Coey JMD.;Balcells L.;Putris FF.;Barry A.;Berkowitz AE. .Magnetoresistance of chromium dioxide powder compacts[J].Physical review letters,1998(17):3815-3818. |
[10] | Chen P;Xing D Y;Du Y W et al.Giant room-temperature magnetoresistance in polycrystalline Zn0.41Fe2.59O4 with α-Fe2O3 grain boundaries[J].Physical Review Letters,2001,87:107202. |
[11] | Feng Jing,Bo Qibing,Che Ping,WANG Jingping,Liu Jianfen,Lu Minfeng,Zhang Deping,Fang Daqing,Cao Xueqiang,MENG Jian.A New Family of Ce6MoO15 as Fast Oxide Ion Conductor[J].稀土学报(英文版),2004(z2):95-97. |
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%