Anharmonic effects on lattice resonant modes of impure metallic crystals |
| |
Authors: | S K Roy N Kundu |
| |
Institution: | (1) Department of Physics, Visva-Bharati University, 731 235 Santiniketan, India |
| |
Abstract: | The effect of lattice anharmonicity on the resonant modes of dilute impurities for Au-Cu, Au-Ag and W-Cr metallic systems
are studied from the poles of the double time temperature dependent impure Green’s function of these crystals. The third order
force constants used in the present work are derived assuming the systems to obey the Lennard-Jones potential. The inclusion
of lattice anharmonicity has been found to increase the resonant frequency which depends upon the mass defect, force constant
change parameter and the impurity concentration terms. Some interesting features about the phase shift and the change in width
of the vibrational spectrum are reported at room temperature for the isotopic defects and the defects interacting with host
atoms. The results are found to be in qualitative agreement with the experiments on the systems considered. |
| |
Keywords: | Resonant modes mass defect force constant phase shift |
本文献已被 SpringerLink 等数据库收录! |