用电子束反应蒸镀法在低温生长了Zn1-xCoxO薄膜.Co含量x高达0.33的Zn1-xCoxO薄膜仍具有类ZnO的纤锌矿结构,没有杂质相,Co的化合价为+2.场冷和零场冷M-T及M-H曲线表明,Zn1-xCoxO(x=0.33)薄膜在低温下具有铁磁性;随着温度的升高,其剩磁和矫顽力均逐渐下降,在65 K以上趋于零,显示出超顺磁性.Zn1xCoxO薄膜的低温铁磁性起源于Co2+离子之间的双交换相互作用及载流子诱导的sP d交换耦合作用,而从低温(＜65 K)铁磁态到高温(＞65 K)超顺磁态的转变可归因于薄膜的纳米晶小尺寸效应.
参考文献
| [1] | J.K.Furdyna,Diluted magnetic semiconductors,J.Appl.Phys.,64,R29(1988) |
| [2] | T.Dietl,H.Ohno,F.Matsukura,J.Cibert,D.M.Terger,Zener model description of ferromagnetism iu zinc -blende magnetic semiconductors,Science,287,1019(2000) |
| [3] | Z.Jin,T.Fukumura,M.Kawasaki,High throughput fabrication of transition-metal-doped epitaxial ZnO thin films:A series of oxide-diluted magnetic semiconductors and their properties,Appl.Phys.Lett.,78,3824(2001) |
| [4] | S.J.Han,B.Y.Lee,J.S.Ku,Y.B.Kim,Y.H.Jeong,Magnetic properties of Zn1-xCoxO,J.Magn.Magn.Mater.,272～276,2008(2004) |
| [5] | K.Ueda,H.Tabata,T.Kawai,Magnetic and electric properties of transition-metal-doped ZuO films,Appl.Phys.Lett.,79,988(2001) |
| [6] | A.Dinia,G.Schmerber,V.Pierron-Bohnes,C.Mény,P.Panissod,E.Beaurepaire,Magnetic perpendicular anisotropy in sputtered (Zn0.75 Co0.25)O dilute magnetic semiconductor,J.Magn.Magn.Mater.,286,37(2005) |
| [7] | S.W.Lim,D.K.Hwang,J.M.Myoung,Observation of optical properties related to room-temperature ferromagnetism in co-sputtered Zn1-xCoxO thin films,Solid State Commun.,125,231(2003) |
| [8] | K.Sato,H.K.Yoshida,Material design for transparent ferromagnets with ZnO-based magnetic semiconductors,Jpn.J.Appl.Phys.Part,2,39,L555(2000) |
| [9] | Z.G.Yin,N.F.Chen,C.L.Chai,F.Yang,Structural and magnetic properties of insulating Zn1-xCoxO thin films,J.Appl.Phys.,96,5093(2004) |
| [10] | YU Ping,WU Huizhen,CHEN Naibo,XU Tianniug,Growth of cubic MgxZn1-xO films and characterization,Chinese Journal of Materials Research,19,277(2005)(余萍,吴惠桢,陈奶波,徐天宁,立方MgxZn1-xO晶体薄膜的制备和性能,材料研究学报,19,277(2005)) |
| [11] | S.W.Yoon,S.B.Cho,S.C.We,S.Yoon,B.J.Suh,Magnetic properties of ZnO-based diluted magnetic semiconductors,J.Appl.Phys.,93,7879(2003) |
| [12] | J.H.Kim,H.Kim,D.Kim,Y.E.Ihm,W.K.Choo,Magnetic properties of epitaxially grown semiconducting Zn1-xCoxO thin films by pulsed laser deposition,J.Appl Phys.,92,6066(2002) |
| [13] | H.J.Lee,S.Y.Jeong,C.R.Cho,C.H.Park,Study of diluted magnetic semiconductor:Co-doped ZnO,Appl.Phys.Lett.,81,4020(2002) |
| [14] | K.J.Kim,Y.R.Park,Spectroscopic ellipsometry study of optical transitions in Zn1-xCoxO alloys,Appl Phys.Lett.,81,1420(2002) |
| [15] | D.L.Leslie-Pelecky,R.D.Rieke,Magnetic properties of nanostructured materials,Chem.Mater.,8,1770(1996) |
| [16] | M.Venkatesan,C.B.Fitzgerald,J.G.Lunnery,J.M.D.Coey,Anisotropic ferromagnetism in substituted zinc oxide,Phys.Rev.Lett.,93,177206(2004) |
| [17] | J.H.Kim,J.B.Lee,H.Kim,D.Kim,Y.Ihm,W.K.Choo,Characteristics of cobalt-doped zinc oxide thin films prepared by pulsed laser deposition,IEEE Trans.Magn.,38,2880(2002) |
| [18] | J.H.Park,M.G.Kim,H.M.Jang,S.Ryu,Y.M.Kim,Cometal clustering as the origin of ferromagnetism in Codoped ZnO thin films,Appl.Phys.Lett.,84,1338(2004) |
| [19] | J.H.Kim,H.Kim,D.Kim,Y.E.Ihm,W.K.Choo,The origin of room temperature ferromagnetism in cobalt-doped zinc oxide thin films fabricated by PLD,J.Europ.Ceramic Soc.,24,1847(2004) |
| [20] | C.D.Wagner,W.M.Riggs,L.E.Davis,J.F.Moulder,Handbook of X-ray Photoelectron Spectroscopy,G.E.Mulenberg ed.(Perkin-Elmer,1979) p.78 |
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