Molecular dynamics study on the stability of amorphous Ar inside a nanopore

Confined solids often show unusual behavior not seen in the bulk solids. In the present paper, we report on molecular dynamics simulations which show that amorphous Ar characterized by local icosahedral configurations is stable inside a nanopore of 3.4 nm in diameter. Although bulk amorphous Ar is vulnerable in the sense that it easily crystallizes after the annealing at 48 K for only 0.3 ns or less, no crystallization is observed in the annealing simulations of confined amorphous Ar for 40 ns or more. The origin of the high stability of confined amorphous Ar is discussed.