title: Solid phase stability of a double-minimum interaction potential system.
abstract: We study phase stability of a system with double-minimum interaction potential in a wide range of parameters by a thermodynamic perturbation theory. The present double-minimum potential is the Lennard-Jones-Gauss potential, which has a Gaussian pocket as well as a standard Lennard-Jones minimum. As a function of the depth and position of the Gaussian pocket in the potential, we determine the coexistence pressure of crystals (fcc and bcc). We show that the fcc crystallizes even at zero pressure when the position of the Gaussian pocket is coincident with the first or third nearest neighbor site of the fcc crystal. The bcc crystal is more stable than the fcc crystal when the position of the Gaussian pocket is coincident with the second nearest neighbor sites of the bcc crystal. The stable crystal structure is determined by the position of the Gaussian pocket. These results show that we can control the stability of the solid phase by tuning the potential function.
authors.affiliation: Department of Physics, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Suematsu
authors.affiliation: Department of Physics, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Yoshimori
authors.affiliation: Department of Physics, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Saiki
authors.affiliation: Department of Physics, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Matsui
authors.affiliation: School of Science and Engineering, Tokyo Denki University, Hatoyama, Saitama 350-0394, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Odagaki