Size-dependent melting behavior of Zn nanowire arrays

Abstract

The melting behavior of Zn nanowires embedded in the holes of porous anodic alumina membrane with different diameters was studied by using the differential scanning calorimetry. The crystalline structure and morphology of Zn nanowire arrays were characterized by x-ray diffraction and transmission electron microscopy. The melting temperature of Zn nanowire arrays shows the strong dependence on nanowire sizes. The melting temperature was curvilinear with the reciprocal of the diameter of nanowires with the change of the diameter, which was discussed in terms of size-dependent heat of fusion change.

Size dependency of melting point of crystalline nano particles and nano wires: A thermodynamic modeling

“…Indeed, the size dependency of heat of fusion was experimentally confirmed by Lai et al [12], who measured the heat of fusion of Sn nano particles of various sizes, proposed a mathematical expression for the effect's size dependency, and predicted the melting point depression in good agreement with experimental data. This expression has been also applied successfully to the predictions for Zn nanowires [16]. However, the expression for the size dependency of heat of fusion involves a model parameter which can only be determined by fitting to experimental data, which is generally unavailable.…”

“…5 should increase with decreasing particle size. From this point of view, the introduction of size dependency for heat of fusion [12,16] can be regarded as a desired change, while introduction of the constant correction factor [17][18][19] is not enough. [6,7] and the present MD simulation using an MEAM interatomic potential [22].…”

“…Besides, these models cause a contradiction for solid particles of a few nanometers, predicting that the particles should be liquid instead of solid [20]. Recently, some models based on the two-phase equilibrium [4] but modified by introducing the size and/or temperature dependency of thermodynamic quantities were developed [16][17][18][19]. For example, Wang et al [16] introduced a size dependency to the latent heat considering the formation of liquid film on the solid surface as was done in a three-phase equilibrium model [12].…”

“…Recently, some models based on the two-phase equilibrium [4] but modified by introducing the size and/or temperature dependency of thermodynamic quantities were developed [16][17][18][19]. For example, Wang et al [16] introduced a size dependency to the latent heat considering the formation of liquid film on the solid surface as was done in a three-phase equilibrium model [12]. Tanaka and coworkers [17][18][19] introduced a correction factor to the resultant melting point depression.…”

“…Hence, several models [2,[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] have been suggested in order to predict the size dependency of melting points more accurately. Some models are based on thermodynamic equilibrium among three phases, solid, liquid, and vapor; others are based on two phases, solid and liquid.…”