TY - JOUR
T1 - Heterojunctions between metals and carbon nanotubes as ultimate nanocontacts
AU - Rodriguez-Manzo, Julio A.
AU - Banhart, Florian
AU - Terrones, Mauricio
AU - Terrones, Humberto
AU - Grobert, Nicole
AU - Ajayan, Pulickel M.
AU - Sumpter, Bobby G.
AU - Meunier, Vincent
AU - Wang, Mingsheng
AU - Bando, Yoshio
AU - Golberg, Dmitri
PY - 2009/3/24
Y1 - 2009/3/24
N2 - We report the controlled formation and characterization of het- erojunctions between carbon nanotubes and different metal nanocrystals (Fe, Co, Ni, and FeCo). The heterojunctions are formed from metal-filled multiwall carbon nanotubes (MWNTs) via intense electron beam irradiation at temperatures in the range of 450700 °C and observed in situ in a transmission electron microscope. Under irradiation, the segregation of metal and carbon atoms occurs, leading to the formation of heterojunctions between metal and graphite. Metallic conductivity of the metal-nanotube junctions was found by using in situ transport measurements in an electron microscope. Density functional calculations show that these structures are mechanically strong, the bonding at the interface is covalent, and the electronic states at and around the Fermi level are delocalized across the entire system. These properties are essential for the application of such heterojunctions as contacts in electronic devices and vital for the fabrication of robust nanotube-metal composite materials.
AB - We report the controlled formation and characterization of het- erojunctions between carbon nanotubes and different metal nanocrystals (Fe, Co, Ni, and FeCo). The heterojunctions are formed from metal-filled multiwall carbon nanotubes (MWNTs) via intense electron beam irradiation at temperatures in the range of 450700 °C and observed in situ in a transmission electron microscope. Under irradiation, the segregation of metal and carbon atoms occurs, leading to the formation of heterojunctions between metal and graphite. Metallic conductivity of the metal-nanotube junctions was found by using in situ transport measurements in an electron microscope. Density functional calculations show that these structures are mechanically strong, the bonding at the interface is covalent, and the electronic states at and around the Fermi level are delocalized across the entire system. These properties are essential for the application of such heterojunctions as contacts in electronic devices and vital for the fabrication of robust nanotube-metal composite materials.
KW - Composites
KW - Conductivity electron microscopy
KW - Interfacial interactions
KW - Nanoelectronics
UR - http://www.scopus.com/inward/record.url?scp=63849272894&partnerID=8YFLogxK
U2 - 10.1073/pnas.0900960106
DO - 10.1073/pnas.0900960106
M3 - Article
AN - SCOPUS:63849272894
SN - 0027-8424
VL - 106
SP - 4591
EP - 4595
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 12
ER -