Controlled size and density distribution of nanoparticles by thermal ammonia etching method

Abstract

Nickel nanometer catalyst thin films were prepared on SiO₂/Si substrates using sputtering coater. The effects of ammonia pretreatment on the catalyst films from continuous film to the nanoparticles were investigated. The nanostructures of the Ni thin films as a function of the catalyst film original thickness, the pretreatment time and temperature were discussed. The optimum parameters of etching process were obtained, and the functional mechanism of ammonia was primarily analyzed. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to evaluate the obtained nanoparticles. It is demonstrated that the controlled size and density distribution of the nanoparticles can be achieved by employing ammonia etching method.

Keywords

ammonia etching / nanoparticle / density control / thermal expansion

References

[1] Han J. H., Yang W. S., Yoo J. B., . Growth and Emission Characteristics of Vertically Well-aligned Carbon Nanotubes Grown on Glass Substrate by Hot Filament Plasma-enhanced Chemical Vapor Deposition[J]. J. Appl. Phys., 2000, 88: 7 363-7 365.

[2] Choi Y. C., Shin Y. M., Lee Y. H., . Controlling the Diameter, Growth Rate,and Density of Vertically Aligned Carbon Nanotubes Synthesized by Microwave Plasma-enhanced Chemical Vapor Deposition[J]. Appl. Phys. Lett., 2000, 76: 2 367-2 369.

[3] Choi Y. C., Shin Y. M., Lim S. C., . Effect of Surface Morphology of Ni Thin Film on the Growth of Aligned Carbon Nanotubes by Microwave Plasma-enhanced Chemical Vapor Deposition[J]. J. Appl. Phys., 2000, 88: 4 898-4 903.

[4] Li G., Zhou M., Ma W. W., . Synthesis of Aligned Carbon Nanotubes by Thermal Chemical Vapor Deposition[J]. J. of Wuhan University of Technology-Mater. Sci.Ed., 2009, 24(1): 15-19.

[5] Choi Y.C., Kim D. W., Lee T. J., . Growth Mechanism of Vertically Aligned Carbon Nanotubes on Silicon Substrates[J]. Synth. Metals, 2001, 117: 81-86.

[6] Haynes C. L., Duyne R. P. J. V. Nanosphere Lithography: a Versatile Nanofabrication Tool for Studies of Size-dependent Nanoparticle Optics[J]. J. Phys. Chem. B, 2001, 105: 5 599-5 611.

[7] Huang Z. P., Carnahan D. L., Rybczynski J., . Growth of Large Periodic Arrays of Carbon Nanotube[J]. Appl. Phys. Lett., 2003, 82: 460-462.

[8] Kempa K., Kimball B., Rybczynski J., . Photonic Crystals Based on Periodic Arrays of Aligned Carbon Nanotubes[J]. Nano. Lett., 2003, 3: 13-18.

[9] Z F Ren, Z P Huang, J W Xu, et al. Large Arrays of Well-aligned Carbon Nanotubes[C]. Proc.13 ^th International Winter School on Electronic Properties of Novel Materials, 1999

[10] Gao J. S., Umeda K., Uchino K., . Plasma Breaking of Thin Films into Nano-sized Catalysts for Carbon Nanotube Synthesis[J]. Mater. Sci.Engin. A, 2003, 352: 308-313.

[11] Henley S. J., Poa C. H. P., Adikaari A. A. D. T., . Excimer Laser Nanostructuring of Nickel Thin Films for the Catalytic Growth of Carbon Nanotubes[J]. Appl. Phys. Lett., 2004, 84: 4 035-4 037.

[12] Ren Z. F., Huang Z. P., Xu J. W., . Synthesis of Large Arrays of Well-aligned Carbon Nanotubes on Glass[J]. Science, 1998, 282: 1 105-1 107.

[13] Lee C. J., Lyu S. C., Cho Y. R., . Diameter-controlled Growth of Carbon Nanotubesusing Thermal Chemical Vapor Deposition[J]. Chem. Phys. Lett., 2001, 341: 245-249.

[14] Shin Y. M., Jeong S. Y., Jeong H. J., . Influence of Morphology of Catalyst Thin Film on Vertically Aligned Carbon Nanotube Growth[J]. J. Crys. Growth, 2004, 271: 81-89.

[15] Liu H. P., Cheng G. A., Zhao Y., . Controlled Growth of Fe Catalyst Film for Synthesis of Vertically Aligned Carbon Nanotubes by Glancing Angle Deposition[J]. Surf. Coat. Techn., 2006, 201: 938-942.

[16] Bower C., Zhou O., Zhu W., . Nucleation and Growth of Carbon Nanotubes by Microwave Plasma Chemical Vapor Deposition[J]. Appl. Phys. Lett., 2000, 77: 2 767-2 769.

[17] Merkulov V. I., Lowndes D. H., Wei Y. Y., . Patterned Growth of Individual and Multiple Aligned Carbon Nanofibers[J]. Appl. Phys. Lett., 2000, 76: 3 555-3 557.