Proceedings of the Indian Academy of Sciences - Section A

Murti, P.; Seshadri, T.

doi: 10.1007/BF03046074pmid: N/A

Raman, C.

doi: 10.1007/BF03046075pmid: N/A

Raman, C.

doi: 10.1007/BF03046076pmid: N/A

Raman, C.; Nilakantan, P.

doi: 10.1007/BF03046077pmid: N/A

Pisharoty, P.

doi: 10.1007/BF03046078pmid: N/A

Vinkatiswaran, C.

doi: 10.1007/BF03046079pmid: N/A

The Raman reflections of X-rays by carborundum, rock-salt, sodium nitrate and penta-crythritol are obtained at liquid air temperature with a specially designed vacuum X-ray camera and their intensities, are compared with those at room temperature. For rock-salt an intermediate temperature of solid carbon dioxide and for carborundum two higher temperatures namely 600° and 900° T have also been employed. From the relative intensities of these reflections at various temperatures, the infra-red frequency active in the particular reflection is ascertained in each case making use of the following formula

Vinkahswaran, C.

doi: 10.1007/BF03046080pmid: N/A

Venkateswaran, C.

doi: 10.1007/BF03046081pmid: N/A

Venkateswaran, C.

doi: 10.1007/BF03046082pmid: N/A

Venkateswaran, C.

doi: 10.1007/BF03046083pmid: N/A

The X-ray reflections from the (110), (200), (211) and (111) planes of hexamethyl-tetramine shows that the intensities of the dynamic reflections follow the same order as the intensities of the corresponding static reflections. The Raman spots of the crystal are relatively sharp compared to those from organic and inorganic crystals of complicated structure. These observations are readily explained by the fact that the molecular and the crystal structures of the substance have a high order of symmetry and that for the principal planes there is only one Raman X-ray active lattice vibration which corresponds to a movement of the two molecules against each other along the cube diagonal. The geometry and orientation of the spots are also found to depend on the direction of the phase-waves connected with the above vibration.