par Tam, Enrico 
;Podsiadlo, Paul;Shevchenko, Elena;Ogletree, Frank D.F.;Delplancke, Marie-Paule ;Ashby, Paul David
Référence Nano letters, 10, 7, page (2363-2367)
Publication Publié, 2010-07
;Podsiadlo, Paul;Shevchenko, Elena;Ogletree, Frank D.F.;Delplancke, Marie-Paule ;Ashby, Paul DavidRéférence Nano letters, 10, 7, page (2363-2367)
Publication Publié, 2010-07
Article révisé par les pairs
| Résumé : | We report the first nanoindentation studies of well-ordered nanocrystal supercrystals composed of 7 nm lead sulfide nanocrystals stabilized with oleic acid ligands as a model system. Their modulus and hardness were found to be similar to hard polymers at 1.7 GPa and 70 MPa, respectively, and the fracture toughness was 40 KPa/m1/2, revealing the brittle nature of these materials. The mechanical properties are dominated by the organic capping agents surrounding the inorganic cores. The close-packed structure distributes stress evenly increasing the modulus and hardness. The relatively short ligands are not likely to be highly interdigitated leading to low dissipation during crack propagation and a low-fracture toughness value. © 2010 American Chemical Society. |
