Optical properties of molybdenum. I. Experiment and Kramers-Kronig analysis

A study of the optical properties and electronic structure of molybdenum is reported in a two-paper experimental and theoretical series. Reflectivity data between 0.5 and 6 eV are presented, and Kramers-Kronig analytical procedures used to determine the optical functions ${\epsilon }_1\left(\omega \right)$ and ${\epsilon }_2\left(\omega \right)$ are discussed. Procedures are discussed for obtaining suitable extrapolations of $R\left(\omega \right)$ in the ranges ${\omega }_{min}\to 0$ and ${\omega }_{max}\to \infty$. (${\omega }_{min}$ and ${\omega }_{max}$ are the energy extremes of the measured spectral range.) A new method (for metals) is presented for optimizing the extrapolation $R\left(\omega \right)$ in the range ${\omega }_{min}\to 0$. Recently reported sum rules are evaluated to test the inversion procedures.