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 Tm and the Debye Temperature θD in metal nanowires and check the validity of Lindeman relation on size reduction that connects these two physical quantities. From direct measurements of the θD and Tm, we show that the depressions in these physical quantities are such that ΔTm(d) and ΔθD2(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 θDTm1/2 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.