TY - JOUR
T1 - Migration of Ag in low-temperature Ag2 S from first principles
AU - Wang, Zhongchang
AU - Gu, Tingkun
AU - Kadohira, Takuya
AU - Tada, Tomofumi
AU - Watanabe, Satoshi
PY - 2008
Y1 - 2008
N2 - Using the density-functional theory combined with the nudged elastic band method, we have calculated migration pathways and estimated the activation energy barriers for the diffusion of Ag ions in low-temperature Ag2 S. The activation energy barriers for four essential migrations for an Ag ion, namely, from a tetrahedral (T) site to an adjacent T vacancy (VT), from an octahedral (O) site to an adjacent O vacancy (VO), from T to VO, and from O to VT, are estimated as 0.461, 0.668, 0.212, and 0.318 eV, respectively, which are comparable to experimental values. This means that diffusions of Ag ions between nonequivalent sites are preferable to those between equivalent sites, and that direct T- VT and O- VO diffusions are less likely to occur than indirect T- VO -T and O- VT -O diffusions. These diffusion behaviors between nonequivalent sites have also been supported by ab initio molecular dynamics simulations, in which the diffusion pathways are directly observed.
AB - Using the density-functional theory combined with the nudged elastic band method, we have calculated migration pathways and estimated the activation energy barriers for the diffusion of Ag ions in low-temperature Ag2 S. The activation energy barriers for four essential migrations for an Ag ion, namely, from a tetrahedral (T) site to an adjacent T vacancy (VT), from an octahedral (O) site to an adjacent O vacancy (VO), from T to VO, and from O to VT, are estimated as 0.461, 0.668, 0.212, and 0.318 eV, respectively, which are comparable to experimental values. This means that diffusions of Ag ions between nonequivalent sites are preferable to those between equivalent sites, and that direct T- VT and O- VO diffusions are less likely to occur than indirect T- VO -T and O- VT -O diffusions. These diffusion behaviors between nonequivalent sites have also been supported by ab initio molecular dynamics simulations, in which the diffusion pathways are directly observed.
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U2 - 10.1063/1.2814245
DO - 10.1063/1.2814245
M3 - Article
C2 - 18190209
AN - SCOPUS:38049095543
VL - 128
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
SN - 0021-9606
IS - 1
M1 - 014704
ER -