纳米固体相稳定性

Incorporating the recent bond order-length-strength correlation mechanism [Sun, et al., J. Phys. Chem. B 106, 10701 (2002)] into the Ising premise has led to consistent insight, with an analytical expression, into the Curie temperature (TC) suppression of ferromagnetic, ferroelectric and superconductive nanosolids. The phase stability is related to the atomic cohesive/exchange energy that is lowered by the coordination number (CN) imperfection of the lower-coordinated atoms near the surface edge. Numerical match between predictions and measurements for a number of specimens reveals that the short spin-spin correlation dominates the exchange interaction in the ferromagnetic Fe, Co, Ni, and Fe3O2 nanosolids, while the long-range interaction dominates the exchange energy for the ferroelectric PbTiO3, PbZrO3, SrBi2Ta2O9, and BaTiO3, and the superconductive MgB2 nanosolids.