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In situ atomic-scale observation of melting point suppression in nanometer-sized gold particles

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Date10-02-02 14:44 Hit5,944

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Figure 1. A typical example showing successive stages of diminution of a Au particle on a graphite substrate maintained at 1100 K. The numbers inserted in each micrograph indicate relative times in seconds. During the diminution, a crystalline-to-liquid phase transition (i.e., melting) occurred at the particle size of approximately 5 nm(d).


The Korea Institute of Materials Science (KIMS) and the University of Osaka, Japan succeeded in the observation of melting point suppression in nanometer-sized gold particles. In this work, real-time, atomic-scale direct observation of melting point suppression in nanometer-sized Au particles, along with simple size reduction, was carried out by means of in situ high resolution electron microscopy. Namely, it was confirmed in real space on an atomic scale that a solid-to-liquid transition occurred when the size of a particle, placed on a graphite substrate maintained at 1100 K, decreased to 5 nm during diminution. Furthermore, a monolayer-thick hole was formed on the substrate at the position of the liquid Au particle, probably due to carbon dissolution into the liquid Au particle. This technology will contribute to increase the reliability of related parts and components by measuring the melting point of nanometer-sized gold particles precisely. Especially, reliability of the product in the field of printing, IT, and Bio industries will be improved revolutionary.


[Contact]


Dr. Junggoo Lee (jglee36@kims.re.kr)


Functional Materials Division


Korea Institute of Materials Science