結晶界面の熱抵抗の分子動力学シミュレーション(<小特集>異相界面における諸現象の物理)

抄録

Non-equilibrium molecular dynamics computer simulation was carried out to investigate a thermal resistance phenomenon at interfaces of Lennard-Jones particle crystals. Inside an FCC crystal, one-dimensional steady thermal energy flow was realized using a pair of temperature-controlled heat-baths. Four types of sharp and flat interfaces between the following crystals were investigated : (i) crystals with different particle masses, (ii) crystals with different interaction parameters, (iii) crystals with various surface interaction parameters, and (iv) crystals with different size parameters. Except for the case (iv), observed temperature profiles have a discontinuity at the interface, from which the temperature gap T_gap is evaluated. Due to the temperature discontinuity, the thermal energy flux is smaller than that through a single crystal without an interface. The observed reduction of the energy flux is larger than that predicted with a simple acoustic model. Interfaces with finite width, or composistion gradient, were also examined.