Link between depressions of melting temperature and Debye temperature in nanowires and its implication on Lindeman relation

摘要

In this paper we investigate a possible link between the depressions of the melting temperature T_m and the Debye Temperature O_D in metal nanowires and check the validity of Lindeman relation on size reduction that connects these two physical quantities. From direct measurements of the O_D and T_m, we show that the depressions in these physical quantities are such that ΔT_m(d) and ΔO_D~2(d) have nearly the same inverse power law dependence on the diameter d (with the exponent ≈-0.6) for nanowires with diameters down to 30 nm. However the ratio O_D/(T_m~(1/2)) is strictly not constant showing a reduction of nearly 9% when the sample size is taken from bulk to 30 nm. We discuss the physical significance of this observation and its impact on Lindeman criterion for melting.