Defects in amorphous Si1-xGex alloys: An explanation of electron spin resonance signals
Department of Physics and Semiconductor Physics Research Center,
Jeonbuk National University, Jeonju 561-756, R. O. Korea
2 Department of Physics, Wonkwang University, Iksan 570-749, R. O. Korea
Accepted: 9 September 1997
We generate amorphous alloys for various Ge compositions by the simulated quenching method using the first-principles molecular-dynamics approach. We find that dangling bonds at Ge sites dominate the local defect structures in a wide range of Ge compositions of x ≥ 0.15, although their backbonding states change with Ge composition. This is due to the minimization of strain energy by having dangling bonds at Ge sites in the network. By postulating that only dangling bonds contribute to the g-value, the calculated g-values are in excellent agreement with the observed ones.
PACS: 61.72.Hh – Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.) / 71.15.Pd – Molecular dynamics calculations (Car-Parrinello) and other numerical simulations / 71.55.Jv – Disordered structures; amorphous and glassy solids
© EDP Sciences, 1997