RESUMEN
A thermodynamic model for the diameter- and length-dependent melting temperature Tm(D,L) of nanorods has been proposed from the perspective of the Gibbs free energy together with the size-dependent interface energy, where D and L denote the diameter and the length of the nanorods. As the model describes, Tm(D,L) decreases with a decrease in D and L, where the diameter effect is dominant while the length effect is secondary. Agreements between model predictions and the available experimental and molecular dynamics simulation results can be found for Sn and Cu nanorods, which enabled us to determine the size dependence of the magnetostructural transition temperature in MnBi nanorods. This work is helpful for the design and application of nanoscale devices.
RESUMEN
With structural miniaturization down to the nanoscale, some detectable parameters of materials no longer remain constant. For NiO nanoparticles example, Raman shift and Néel temperature increase while optical band gap decreases with increasing the nanoparticle size. Herein, we developed the analytic models to describe the size dependence of these above-mentioned seemingly uncorrelated parameters for NiO nanoparticles, based on the average coordination number-dependent cohesive energy model. Consistency between our theoretical predictions and the corresponding experimental results not only verified the accuracy of our developed models but also provided insight into the essentiality of cohesive energy in describing the effect of size on the materials properties of NiO nanoparticles.