Size Segregation and Super-Domain Mediated by Dipolar Interactions in 3-D Iron Nanoparticle Assemblies
SI Ping-Zhan1**,WANG Hai-Xia1,JIANG Wei1,CHEN Chun-Qiang1,HU Xiu-Kun1,LIU Jin-Jun2,LEE Jung-Goo3,CHOI Chul-Jin3
1School of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 2Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211 3Korea Institute of Materials Science, Changwon, Gyeongnam, 641-831, R. Korea
Size Segregation and Super-Domain Mediated by Dipolar Interactions in 3-D Iron Nanoparticle Assemblies
SI Ping-Zhan1**,WANG Hai-Xia1,JIANG Wei1,CHEN Chun-Qiang1,HU Xiu-Kun1,LIU Jin-Jun2,LEE Jung-Goo3,CHOI Chul-Jin3
1School of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 2Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211 3Korea Institute of Materials Science, Changwon, Gyeongnam, 641-831, R. Korea
摘要We report the phenomenon of size segregation and the experimental evidence for the presence of correlated areas mediated by dipolar interactions in three-dimensional Fe nanoparticle assemblies. Iron nanoparticles dispersed in ethanol assemble into tabular whiskers (8µm×40µm in cross section with lengths up to 10 cm) due to dipolar interactions. Magnetic force microscopy observations on iron nanoparticle compact assemblies prove the local magnetic correlation of the Fe nanoparticles due to dipolar coupling and the formation of domain-like structures in expanded dimensions. Magnetic measurements show that the coercivity and the low field magnetic susceptibility of the Fe nanoparticle assemblies increase while the saturation magnetization decreases with the increasing inter-particle distance.
Abstract：We report the phenomenon of size segregation and the experimental evidence for the presence of correlated areas mediated by dipolar interactions in three-dimensional Fe nanoparticle assemblies. Iron nanoparticles dispersed in ethanol assemble into tabular whiskers (8µm×40µm in cross section with lengths up to 10 cm) due to dipolar interactions. Magnetic force microscopy observations on iron nanoparticle compact assemblies prove the local magnetic correlation of the Fe nanoparticles due to dipolar coupling and the formation of domain-like structures in expanded dimensions. Magnetic measurements show that the coercivity and the low field magnetic susceptibility of the Fe nanoparticle assemblies increase while the saturation magnetization decreases with the increasing inter-particle distance.
[1] Trohidou K and Vasilakaki M 2010 Acta Phys. Polonica A 117 374[2] Serantes D, Baldomir D, Pereiro M, Hernando B, Prida V M, Llamazares J L S, Zhukov A, Ilyn M and González J 2009 J. Phys. D: Appl. Phys. 42 215003[3] Bliznyuk V, Singamaneni S, Sahoo S, Polisetty S, He X and Binek C 2009 Nanotechnology 20 105606[4] Puntes V F, Gorostiza P, Aruguete D M, Bastus N G and Alivisatos A P 2004 Nature Mater. 3 263[5] Lee D C, Smith D K, Heitsch A T and Korgel B A 2007 Annu. Rep. Prog. Chem.: Sect. C: Phys. Chem. 103 351[6] Kasyutich O, Desautels R D, Southern B W and Lierop J V 2010 Phys. Rev. Lett. 104 127205[7] Rosato A, Strandburg K J, Prinz F and Swendsen R H 1987 Phys. Rev. Lett. 58 1038[8] Metzger M J, Remy B and Glasser B J 2011 Powder Technol. 205 42[9] Si P Z, Škorvánek I, Kováč J, Geng D Y, Zhao X G and Zhang Z D 2003 J. Appl. Phys. 94 6779[10] Si P Z, Choi C J, Tegus O, Brück E, Geng D Y and Zhang Z D 2008 J. Nanopart. Res. 10 53[11] Bean C P and Livingston J D 1959 J. Appl. Phys. 30 S120[12] Allia P, Coisson M, Knobel M, Tiberto P and Vinai F 1999 Phys. Rev. B 60 12207[13] Kechrakos D and Trohidou K N 1998 Phys. Rev. B 58 12169
2012, Vol. 29 
