• R C Naik

      Articles written in Proceedings – Section A

    • The1I6 state of Pr3+ in LaCl3 at 77°K

      R M Agrawal R K Asundi R C Naik D Ramakrishnan Shobha Singh

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      A single crystal of 5% Pr3+ in LaCl3 was grown by Stockbarger’s method and its absorption spectrum at 77° K. recorded in the region 4200–5400 Å on a grating spectrograph having a dispersion of 5 Å/mm. in the first order. Polarization of the absorption lines has also been obtained. In the group of lines arising from1I63H4 transition, six more lines in addition to the four previously known have been observed. Satisfactory analysis of all these ten lines is given. One additional Stark level in1I6 is established at 21407 cm.−1 withμ=1. For a few lines the polarization results obtained here do not agree with those of previous workers but fit in satisfactorily in the analysis.

    • Ultra-violet absorption spectra and higher excited states of Nd3+ in LaCl3 at 77° K.

      R M Agrawal R K Asundi R C Naik D Ramakrishnan Shobha Singh

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      The paper deals with an extension towards shorter wavelengths of the absorption spectrum of Nd3+ employing a 5% Nd3+ doped LaCl3 crystal. Five new groups of lines have been recorded and the analysis and interpretation of one of these groups,viz., group O between 3010 and 3023 Å are given. The lines observed in this group are shown to be due to transitions from the ground level (4I9/2) stark components (μ=5/2, 1/2 and 3/2) to the two stark components (μ=3/2, 1/2) of2D3/2 level at about 33200 cm.−1

    • Absorption and fluorescence spectra of praseodymium in KCl and KBr matrices

      R K Asundi R C Naik P Ramakoteswara Rao

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      The observed fluorescence and absorption spectra of single crystals of KCl and KBr doped with praseodymium (Pr) show that the rare earth enters substitutionally as Pr3+ in these lattices. However, the site symmetry of the ion has at most a twofold axis. This is shown by the fact that thej-degeneracy of its energy levels is completely removed. Fluorescence is observed to occur only from3P0 level to3F2, 3, 4 and3H6 levels. The overall Stark splitting shows that the Pr3+ ion experiences a stronger field in these matrices than in LaCl3 or LaBr3.

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