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Why can nanoscale gold melt at a lower temperature than bulk gold?

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The powers of 10 — nanotechnology Examples from biological and mechanical realms illustrate various “orders of magnitude” (powers of 10), from 10⁻² meter down to 10⁻⁷ meter.

Nanoscale gold melts at a lower temperature than bulk gold primarily due to the physical properties inherent to nanoparticles.

As particles are reduced to the nanoscale (typically 1–100 nm), they exhibit an enormous increase in their specific surface area. A significant percentage of the total atoms in a nanoparticle are located at the surface rather than in the interior bulk of the material. Because surface atoms have fewer neighboring atoms to bond with compared to those in the interior, they are less tightly bound and possess higher energy. This increased surface-to-volume ratio destabilizes the crystalline structure, requiring less thermal energy to transition the material from a solid to a liquid state, thereby lowering the melting point.1