Optical Spectroscopy of the Geometrically Frustrated Pyrochlore Ho2Ti2O7

L. Macalik; M. Maczka; P. Solarz; A.F. Fuentes; K. Matsuhira; Z. Hiroi. Optical Spectroscopy of the Geometrically Frustrated Pyrochlore Ho2Ti2O7. Optical Materials (ISSN 0925-3467). 2009, Vol. 31, p. 704-2009.

<p>Optical absorption and fluorescence spectra of Ho3+ in the geometrically frustrated pyrochlore Ho2Ti2O7 have been measured in the 27000-4000 cm-1 spectral and 295-8 K temperature range. The energy positions of the Stark levels have been deduced. The Judd-Ofelt analysis has been performed by fitting the room temperature absorption spectra and the calculated Judd-Ofelt parameters have been used to evaluate the Ho3+ radiative transition probabilities and the branching ratio. The obtained results show that although the lowest crystal field levels of Ho3+ in Ho2Ti2O7 are well separated, this separation (104 cm-1) is smaller than that previously suggested on the basis of neutron and magnetic studies (150-166 cm-1)</p>