Infrared Studies on Solid Hydrogen, Deuterium and Hydrogen-Deuteride Using Fourier-Transform Spectroscopy.

This experiment was done in a comprehensive way in the sense that 6 different samples in solid state were measured and pure rotational, fundamental, first and second overtone infrared spectra were observed through this study (75 cm^{-1} - 12000 cm^{-1}). The measurements reported here for the first time include: the first and second overtone spectrum of solid HD, the first and second overtone spectrum of solid D_2 . Also, almost complete sets of spectra were observed with higher resolution in the first and second overtones of solid H_2. In the pure rotational band, the R_0(0) line of solid HD was reinvestigated to solve the puzzle existing between theory and experiment and indeed a clear answer was found through this measurement. The spectra observed in the pure rotational and fundamental band are also very useful in examining the previous measurements done with the same samples. As the measurements were done on six different samples (para- and normal-H_2, ortho -, normal- and para-D_2, and HD), the experimental results can be used to study isotopic effects as well as the dependences on different ortho- and para-concentrations. The spectra from the solid samples also contain broad phonon sidebands which follow relatively sharp zero-phonon transitions. Studies of these phonon bands as well as on zero-phonon transitions are done in this experiment.