Nanobeam Mechanics: Elasticity, Strength, and Toughness of Nanorods and Nanotubes

The Young's modulus, strength, and toughness of nanostructures are important to proposed applications ranging from nanocomposites to probe microscopy, yet there is little direct knowledge of these key mechanical properties. Atomic force microscopy was used to determine the mechanical properties of individual, structurally isolated silicon carbide (SiC) nanorods (NRs) and multiwall carbon nanotubes (MWNTs) that were pinned at one end to molybdenum disulfide surfaces. The bending force was measured versus displacement along the unpinned lengths. The MWNTs were about two times as stiff as the SiC NRs. Continued bending of the SiC NRs ultimately led to fracture, whereas the MWNTs exhibited an interesting elastic buckling process. The strengths of the SiC NRs were substantially greater than those found previously for larger SiC structures, and they approach theoretical values. Because of buckling, the ultimate strengths of the stiffer MWNTs were less than those of the SiC NRs, although the MWNTs represent a uniquely tough, energy-absorbing material.

[1]  J. Lu.  Elastic Properties of Carbon Nanotubes and Nanoropes , 1997, cond-mat/9704219.

[2]  M. Lutwyche,et al.  Time-resolved observation of thermal oscillations by transmission electron microscopy , 1997 .

[3]  Luc T. Wille,et al.  Elastic properties of single-walled carbon nanotubes in compression , 1997 .

[4]  Charles M. Lieber,et al.  Nanorod-Superconductor Composites: A Pathway to Materials with High Critical Current Densities , 1996, Science.

[5]  Charles M. Lieber,et al.  Nanomachining, manipulation and fabrication by force microscopy , 1996 .

[6]  Young Hee Lee,et al.  Crystalline Ropes of Metallic Carbon Nanotubes , 1996, Science.

[7]  Charles M. Lieber,et al.  Probing Electrical Transport in Nanomaterials: Conductivity of Individual Carbon Nanotubes , 1996, Science.

[8]  J. Bernholc,et al.  Nanomechanics of carbon tubes: Instabilities beyond linear response. , 1996, Physical review letters.

[9]  A. Maiti,et al.  Structural flexibility of carbon nanotubes , 1996 .

[10]  Pavel Nikolaev,et al.  Catalytic growth of single-walled manotubes by laser vaporization , 1995 .

[11]  Charles M. Lieber,et al.  Synthesis and characterization of carbide nanorods , 1995, Nature.

[12]  C. B. Carter,et al.  Growth and Sintering of Fullerene Nanotubes , 1994, Science.

[13]  David Tománek,et al.  Structural rigidity and low frequency vibrational modes of long carbon tubules , 1993 .

[14]  P. Ajayan,et al.  Large-scale synthesis of carbon nanotubes , 1992, Nature.

[15]  Robertson,et al.  Energetics of nanoscale graphitic tubules. , 1992, Physical review. B, Condensed matter.

[16]  Methfessel,et al.  Calculated elastic constants and deformation potentials of cubic SiC. , 1991, Physical review. B, Condensed matter.

[17]  John J. Petrovic,et al.  Tensile mechanical properties of SiC whiskers , 1985 .

[18]  O. L. Blakslee,et al.  Elastic Constants of Compression-Annealed Pyrolytic Graphite , 1970 .

[19]  W. Webb,et al.  Mechanical behavior of microcrystals , 1958 .

[20]  Conyers Herring,et al.  Elastic and Plastic Properties of Very Small Metal Specimens , 1952 .

[21]  T. Ebbesen,et al.  Exceptionally high Young's modulus observed for individual carbon nanotubes , 1996, Nature.

[22]  Rodney S. Ruoff,et al.  Mechanical and thermal properties of carbon nanotubes , 1995 .

[23]  K. Lafdi,et al.  Flexibility of graphene layers in carbon nanotubes , 1995 .