The atomistic study on the thermal expansion behaviors of nanowires

Models for mean bonding length, melting point and lattice thermal expansion of nanoparticle materials

“…Although many researchers have reported the increase of LTE with the decrease in the size of nanoscale particles [34,35,10], there are others who found out its decrease [10,36]. Reports on experimental values of nanocrystals of Ge show the decrease of LTE with the decrease of the size, namely, it changes from 8 Â 10 À6 K À1 for bulk to 3 Â 10 À6 K À1 for a 4 nm diameter nanoparticle [37].…”

Grain Size-Dependent Thermal Expansion of Nanocrystalline Metals

“…To explain the unusual behavior of CTE, there are mainly two routes that have been adopted in the literature: (i) formulating a nanocrystalline material model [ 19 ] and (ii) employing classical molecular dynamics (CMD) modeling [ 37 , 38 ]. Daniel and coworkers [ 19 ] have proposed a nanocrystalline material model for Cr and CrN, in which nanomaterials should be described via atoms in two discrete regions, i.e., grains and GBs.…”

“…This model is qualitative and appears intuitive, but it has not been quantitively related to direct physical observations. CMD modeling has been carried out for some nanomaterials, including Cu nanowires [ 37 ] as well as Cu, Ag, and Ni nanometer-thick thin films [ 38 ], but no GBs were included in these particular cases. Hence, there is no attempt to critically appraise these approaches simultaneously and explain the unusual behavior of CTE for polycrystals with nanosized grains using both atomistic and electronic structure perspectives.…”