Site-selective spectroscopy ofHo3+ions inCsCdBr3crystals

Abstract

With the use of laser-selective excitation, an extensive set of energy levels has been established for the principal ${\mathrm{Ho}}^{3+}$ dimer center in ${\mathrm{CsCdBr}}_3$:${\mathrm{Ho}}^{3+}$ crystals. The observed splittings of around 2 ${\mathrm{cm}}^{\mathrm{-}1}$ of the transitions to or from energy levels assigned as having ${\gamma }_3$ symmetry under ${\mathit{C}}_{3\mathit{v}}$ symmetry is indicative of deviations of the ${\mathrm{Ho}}^{3+}$ ion-site symmetry from exact ${\mathrm{C}}_{3\mathit{v}}$ symmetry. As for the previously studied ${\mathrm{Er}}^{3+}$ pair center in ${\mathrm{CsCdBr}}_3$, the ${\mathrm{Ho}}^{3+}$ pair center exhibits strong upconversion fluorescence with up to one-third the intensity of the direct fluorescence under cw laser excitation of the ${}_{}{}^5{}_{}{}^{}$ ${\mathit{I}}_8$ ${\to }^5$ ${\mathit{S}}_2$ transition in the green and up to one-fifteenth the intensity for comparable cw laser excitation of the ${}_{}{}^5{}_{}{}^{}$ ${\mathit{I}}_8$ ${\to }^5$ ${\mathit{F}}_5$ transition in the red. Additional small splittings of up to 0.5 ${\mathrm{cm}}^{\mathrm{-}1}$ appear for the sharper transitions and are attributed to the ion-pair interaction. Energy levels are also reported for three varieties of minority centers with one of these centers being present in both 0.3% and 0.1% ${\mathrm{Ho}}^{3+}$ crystals, another in 0.01% ${\mathrm{Ho}}^{3+}$ crystals and the third in ${\mathrm{Na}}^{+}$ codoped crystals. Crystal-field analyses are reported for the principal dimer center and two of the minority centers. Fluorescence lifetimes were determined for several transitions of the dimer center and used to infer energy-transfer rates. Preliminary high-resolution results are reported for the excitation profiles of the two lowest-energy ${}_{}{}^5{}_{}{}^{}$ ${\mathit{I}}_8$ ${\to }^5$

Keywords

• MSUB
• MATHVARIANT
• INLINE
• HTTP
• MSUP
• XMLNS
• WWW.W3.ORG/1998/MATH/MATHML

This publication has 25 references indexed in Scilit:

• Polarization study and crystal-field analysis of the laser-selective excitation spectra of ${\mathrm{Ho}}^{3+}$ ions in ${\mathrm{CaF}}_2$ and ${\mathrm{SrF}}_2$ crystals
  Physical Review B, 1992
• Dynamics and spectroscopy of infrared-to-visible upconversion in erbium-doped cesium cadmium bromide (CsCdBr3:Er3+)
  Physical Review B, 1992
• Comparative Raman Study of Phonon Linewidths in Pure and Lead‐Doped CsCdBr₃
  Physica Status Solidi (b), 1987
• De-excitation processes of optically excited Nd3+ pairs in CsCdBr3
  Journal de Physique, 1987
• Site-selective spectroscopy via energy up-conversion inCaF2:Pr3+
  Physical Review B, 1986
• Transfer inside pairs of Pr3+ in LaF3 studied by up-conversion fluorescence
  Journal de Physique Lettres, 1981
• EPR spectra of magnetically coupled pairs of G${\mathrm{d}}^{3+}$ ions in crystals of CsMg${\mathrm{Cl}}_3$, CsMg${\mathrm{Br}}_3$, and CsCd${\mathrm{Br}}_3$
  Physical Review B, 1977
• EPR spectrum of coupled pairs ofGd3+ions in single crystals of CsCdBr3
  Physical Review B, 1977
• The lattice dynamics of calcium fluoride
  Journal of Physics C: Solid State Physics, 1970
• Vibronic Spectra of Sr${\mathrm{F}}_2$:${\mathrm{Sm}}^{2+}$ and Ba${\mathrm{F}}_2$:${\mathrm{Sm}}^{2+}$
  Physical Review B, 1964

Read more Read more

Cited by 34 articles