RAMAN-SPECTRUM OF SOLID HYDROGEN DEUTERIDE

A Raman spectrometer using a focused laser beam and an external resonator was designed and built to study solid hydrogen samples using Raman scattering. A number of transitions were observed in the spectrum of solid HD, including an R0(0) (DELTAJ= 1) and a T0(0) + S0(0) (DELTAJ1 = 3,DELTAJ2 = 2) transition. The intensity of the latter was 4.4 X 10(-6) relative to the allowed S0(0) line. These transitions occur in HD as a result of the shifted components of the induced polarizability, which arise because of the separation between the center of mass and center of interaction in a HD molecule. Theoretical intensity calculations of both transitions are in very good agreement with measured intensities. A U0(0) (DELTAJ = 4) and U0(0) + S0(0) transition were also observed, but calculations show that the induced polarizability makes a negligible contribution to both transitions. A feature in the vibrational (0-1) band was observed near the expected position of the R1(0) transition, but disagreement between the measured and theoretical intensity and a frequency 7 cm 1 higher than measured in absorption experiments led to its identification as part of the Q(R) phonon band. The observed Q(R) phonon then appeared very similar to the same feature observed in absorption: a multicomponent peak, followed by a dip in intensity, followed by another peak. R(R) phonon bands associated with the R0(0) and R1(0) transitions were also observed with intensities much greater than the zero-phonon lines. Two larger features in the low-frequency wings of the S0(0) and S1(0) lines were observed and evidence was presented for the identification of these features as extensions of the R(R) phonon bands, giving the R(R) phonons a similar appearance to the Q(R) phonon.