Microwave absorption properties and the isotropic antenna mechanism of ZnO nanotrees

In this paper, ZnO nanowires and ZnO nanotrees have been prepared and their microwave absorption properties have been investigated in detail. Complex permittivity and permeability of the ZnO nanostructures and paraffin composites have been measured in a frequency of 0.1–18 GHz. Excellent microwave absorption performances have been observed in ZnO nanotree composite compared to ZnO nanowire composite, and the maximum absorption is enhanced as the concentration of the nanotrees increases in the composite. The value of minimum reflection loss for the composites with 60 vol % ZnO nanotrees is −58 dB at 4.2 GHz with a thickness of 4.0 mm. Such strong absorption is attributed to the unique isotropic antenna morphology of the ZnO nanotrees in the composite.

[1]  M. Matsumoto,et al.  Thin electromagnetic wave absorber for quasi-microwave band containing aligned thin magnetic metal particles , 1997 .

[2]  Yang Liu,et al.  Microwave absorption properties of the carbon-coated nickel nanocapsules , 2006 .

[3]  Chung Yin Kwong,et al.  Photoluminescence and Electron Paramagnetic Resonance of ZnO Tetrapod Structures , 2004 .

[4]  H. Tributsch,et al.  Microwave absorption studies of interface phenomena at ZnO electrodes , 1983 .

[5]  Controllable synthesis of undoped/Cd-doped ZnO nanostructures , 2006 .

[6]  Qing Chen,et al.  Microwave Absorption Enhancement and Complex Permittivity and Permeability of Fe Encapsulated within Carbon Nanotubes , 2004 .

[7]  K. Hu,et al.  Preparation and electromagnetic wave absorption properties of Fe-doped zinc oxide coated barium ferrite composites , 2007 .

[8]  J. Zuo,et al.  Induced growth of asymmetric nanocantilever arrays on polar surfaces. , 2003, Physical review letters.

[9]  L. Olmedo,et al.  Microwave characterization and modelization of magnetic granular materials , 1993 .

[10]  Zuowan Zhou,et al.  Microwave absorption behaviors of tetra-needle-like ZnO whiskers , 2006 .

[11]  E. Jang,et al.  Fine Tuning of the Face Orientation of ZnO Crystals to Optimize Their Photocatalytic Activity , 2006 .

[12]  Jae Hyun Kim,et al.  Hydrothermal Growth of Periodic, Single‐Crystal ZnO Microrods and Microtunnels , 2006 .

[13]  P. Watts,et al.  High Permittivity from Defective Multiwalled Carbon Nanotubes in the X‐Band , 2003 .

[14]  Peidong Yang,et al.  Dendritic nanowire ultraviolet laser array. , 2003, Journal of the American Chemical Society.

[15]  Matthew Mo,et al.  In Situ Self‐Assembly of Thin ZnO Nanoplatelets into Hierarchical Mesocrystal Microtubules with Surface Grafting of Nanorods: A General Strategy towards Hollow Mesocrystal Structures , 2008 .

[16]  Zhong Lin Wang,et al.  Microfibre–nanowire hybrid structure for energy scavenging , 2008, Nature.

[17]  Zhong Lin Wang,et al.  Spontaneous Polarization-Induced Nanohelixes, Nanosprings, and Nanorings of Piezoelectric Nanobelts , 2003 .

[18]  F. Wen,et al.  Microwave permeability spectra of flake-shaped FeCuNbSiB particle composites , 2008 .

[19]  Erik David Spoerke,et al.  Sequential Nucleation and Growth of Complex Nanostructured Films , 2006 .

[20]  Xiao Lin,et al.  Microwave Absorption of Single-Walled Carbon Nanotubes/Soluble Cross-Linked Polyurethane Composites , 2007 .

[21]  Yoke Khin Yap,et al.  Formation of single crystalline ZnO nanotubes without catalysts and templates , 2007 .

[22]  Jun Liu,et al.  Secondary nucleation and growth of ZnO. , 2007, Journal of the American Chemical Society.

[23]  Zhong Lin Wang,et al.  Nanobelts of Semiconducting Oxides , 2001, Science.

[24]  Y. J. Chen,et al.  Microwave absorption properties of the ZnO nanowire-polyester composites , 2004 .

[25]  M. Cao,et al.  Microwave absorption properties and mechanism of cagelike ZnO∕SiO2 nanocomposites , 2007 .

[26]  Yong Ding,et al.  Single-Crystal Nanorings Formed by Epitaxial Self-Coiling of Polar Nanobelts , 2004, Science.

[27]  Lagarkov An,et al.  Electromagnetic properties of composites containing elongated conducting inclusions , 1996 .