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An anomalous alloy: Y_x Si_{1-x}

V. Meregalli·M. Parrinello
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Abstract

We study via density functional-based molecular dynamics the structural and dynamical properties of the rare earth silicon amorphous alloy Y_xSi_{1-x} for x=0.093 and x=0.156. The Si network forms cavities in which a Y^{3+} cation is entrapped. Its electrons are transferred to the Si network and are located in the dangling bonds of the Si atoms that line the Y cavities. This leads to the presence of low coordinated Si atoms that can be described as monovalent or divalent anions. For x=0.156, the cavities touch each other and share Si atoms that have two dangling bonds. The vibrational spectrum is similar to that of amorphous Si. However, doping induces a shoulder at 70 cm^{-1} and a pronounced peak at 180 cm^{-1} due to low coordinated Si.

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V. Meregalli, M. Parrinello. 2000-05-24. An anomalous alloy: Y_x Si_{1-x}. https://doi.org/10.1016/s0038-1098(00)00473-7

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