Mechanochemical synthesis for studying the melting of metallic nanoparticles: a case study of copper

Insignificant influence of the matrix on the melting of incoherently embedded tin and zinc nanoparticles

“…For Zn, γ L is taken as 782 mJ m −2 and ρ L 6.6 g cm −3 according to [59], the product is ΔT m = 236/d, where ΔT m is in K and d in nm, and for Sn, ΔT m = 291/d as was calculated in [49]. From figures 4(a) and (b) it is seen that ( 1) is in principle coinciding with experimental data, as was the case for Fe [22], Cu [23] and mechanically milled In, Sn, Pb, Bi, Cd [18] shown in [49].…”

“…By employing mechanically milled Sn-LiF, Zn-LiF and Zn-Al 2 O 3 systems: (i) the size dependence in the melting of Sn nanoparticles as reported by Sheng et al [18] is confirmed with a different matrix; (ii) available sample systems for studying melting point depression, mainly In, Sn, Pb, Bi and Cd embedded in an Al matrix [18] and Fe [22] and Cu [23] in SiO 2 , are successfully expanded by using mechanically milled metal-nonmetal systems with new data reported on Zn embedded in LiF and Al 2 O 3 ; (iii) on the above basis, we find that different matrices do not show significantly different influences on the melting of Sn and Zn, which is rationalized by examining both the thermodynamics and kinetics of surface-induced melting.…”

“…In addition, the obtained samples were of the order of a gram and were ready for calorimetry measurements that are straightforward, and hence more reliable, for understanding melting. However, regrettably, until very recently [22,23] only five low-melting-point metal elements have been studied using this method, namely In, Sn, Pb, Bi and Cd embedded in an Al matrix [17][18][19][20][21], although there is no limitation on metals that can be selected in an Al matrix (provided they immiscible in solid Al) for preparation of embedded nanoparticles using mechanical alloying. Other methods, for example melt quenching and ion implantation, did not really expand the family of samples for studying size-dependent melting of metals, although some other matrices could be employed, namely Cu [24], Ni [24,25], Zn [26], Al-based metallic glass [28,29] or quasicrystalline matrices [30][31][32][33][34].…”

“…To expand the family of suitable samples for studying size-dependent melting of metals we recently tried to employ nonmetallic matrices [22,23] by using mechanical milling in addition to the well-studied Al matrix. In the case of Fe and Cu nanoparticles embedded in SiO 2 , the mechanochemical synthesis [50] was found to work promisingly.…”