Physical review. B, Condensed matter

Two-photon spectroscopy in GdAlO3

Luiz A. O. Nunes, Sebastião Pádua, J. C. Castro

Published Mar 1, 1990• 1 citation

Abstract

Two-photon absorption spectroscopy is used to study f\ensuremath{\rightarrow}f transitions of the ${\mathrm{Gd}}^{3+}$ ion in pure ${\mathrm{GdAlO}}_{3}$ crystals. This technique allows us to observe the electronic transitions far in the ultraviolet without background as opposed to conventional spectroscopy. We observed several transitions that violated the angular-momentum selection rules \ensuremath{\Delta}J\ensuremath{\le}2.

DOI: 10.1103/physrevb.41.4736

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Physical review. B, Condensed matter

Two-photon spectroscopy in GdAlO3

Luiz A. O. Nunes, Sebastião Pádua, J. C. Castro

Published Mar 1, 1990• 1 citation

Publisher

Abstract

Two-photon absorption spectroscopy is used to study f\ensuremath{\rightarrow}f transitions of the

{\mathrm{Gd}}^{3+}

ion in pure

{\mathrm{GdAlO}}_{3}

crystals. This technique allows us to observe the electronic transitions far in the ultraviolet without background as opposed to conventional spectroscopy. We observed several transitions that violated the angular-momentum selection rules \ensuremath{\Delta}J\ensuremath{\le}2.

DOI: 10.1103/physrevb.41.4736

Related papers

TWO PHOTON SPECTROSCOPY OF ELECTRONIC TSANSITIONS IN PURE GdA10 3

Luiz A. O. Nunes, Joaquim Coutinho Neto

Jul 18, 19880 citations

Third- and fourth-order analysis of the intensities and polarization dependence of two-photon absorption lines of Gd3+ in La F3 and aqueous solution

M. C. Downer, Albert Bivas

A comprehensive report and analysis of our observations of numerous parity-allowed direct two-photon transitions within the $4{f}^{7}$ configuration of the ${\mathrm{Gd}}^{3+}$ ion is presented. The experimental technique is ultraviolet fluorescence detection following optical excitation with a dye-laser beam. Previous results and analyses are extended in three ways. (1) The intensities and polarization dependence of individual Stark components, in addition to integrated multiplet intensities, are reported and analyzed for ${\mathrm{Gd}}^{3+}$ :La ${\mathrm{F}}_{3}$ . In those cases ($^{8}S_{\frac{7}{2}}\ensuremath{\rightarrow}^{6}P_{\frac{5}{2}},^{6}D_{\frac{9}{2},\frac{3}{2},\frac{5}{2}}$) where a second-order theory of two-photon absorption adequately explains the integrated intensity, it also (with the exception of $^{6}D_{\frac{9}{2}}$ ) explains the Stark-component intensities. The remaining transitions are anomalously strong, and in some cases violate the angular momentum selection rules $\ensuremath{\Delta}L,\ensuremath{\Delta}J\ensuremath{\le}2$ and exhibit strong anisotropies, in contradiction to the second-order theory. It is shown that introduction of third- and fourth-order contributions involving spin-orbit and/or crystal-field interactions among levels of the $4{f}^{6}5d$ configuration, which serve as intermediate states, can account for both the integrated and Stark-component intensities of these transitions. (2) The strong anisotropy observed for the transitions $^{8}S_{\frac{7}{2}}\ensuremath{\rightarrow}^{6}P_{\frac{3}{2}},^{6}I_{J},^{6}D_{\frac{1}{2}}$ in ${\mathrm{Gd}}^{3+}$ :La ${\mathrm{F}}_{3}$ is explained quantitatively as a polarization-dependent interference between contributions to the intensity which are comparable in magnitude. Interference is destructive for $\stackrel{\ensuremath{\rightarrow}}{E}\ensuremath{\parallel}\stackrel{^}{z}$ and constructive for $\stackrel{\ensuremath{\rightarrow}}{E}\ensuremath{\perp}\stackrel{^}{z}$, creating an order-of-magnitude contrast in the line strength for the two polarizations. (3) A two-photon excitation spectrum of ${\mathrm{Gd}}^{3+}$ in aqueous solution is reported. Linewidths comparable to those of room-temperature solids and Stark splittings which suggest a low-symmetry quasistatic environment are observed.A comprehensive report and analysis of our observations of numerous parity-allowed direct two-photon transitions within the $4{f}^{7}$ configuration of the ${\mathrm{Gd}}^{3+}$ ion is presented. The experimental technique is ultraviolet fluorescence detection following optical excitation with a dye-laser beam. Previous results and analyses are extended in three ways. (1) The intensities and polarization dependence of individual Stark components, in addition to integrated multiplet intensities, are reported and analyzed for ${\mathrm{Gd}}^{3+}$:La${\mathrm{F}}_{3}$. In those cases ($^{8}S_{\frac{7}{2}}\ensuremath{\rightarrow}^{6}P_{\frac{5}{2}},^{6}D_{\frac{9}{2},\frac{3}{2},\frac{5}{2}}$) where a second-order theory of two-photon absorption adequately explains the integrated intensity, it also (with the exception of $^{6}D_{\frac{9}{2}}$) explains the Stark-component intensities. The remaining transitions are anomalously strong, and in some cases violate the angular momentum selection rules $\ensuremath{\Delta}L,\ensuremath{\Delta}J\ensuremath{\le}2$ and exhibit strong anisotropies, in contradiction to the second-order theory. It is shown that introduction of third- and fourth-order contributions involving spin-orbit and/or crystal-field interactions among levels of the $4{f}^{6}5d$ configuration, which serve as intermediate states, can account for both the integrated and Stark-component intensities of these transitions. (2) The strong anisotropy observed for the transitions $^{8}S_{\frac{7}{2}}\ensuremath{\rightarrow}^{6}P_{\frac{3}{2}},^{6}I_{J},^{6}D_{\frac{1}{2}}$ in ${\mathrm{Gd}}^{3+}$:La${\mathrm{F}}_{3}$ is explained quantitatively as a polarization-dependent interference between contributions to the intensity which are comparable in magnitude. Interference is destructive for $\stackrel{\ensuremath{\rightarrow}}{E}\ensuremath{\parallel}\stackrel{^}{z}$ and constructive for $\stackrel{\ensuremath{\rightarrow}}{E}\ensuremath{\perp}\stackrel{^}{z}$, creating an order-of-magnitude contrast in the line strength for the two polarizations. (3) A two-photon excitation spectrum of ${\mathrm{Gd}}^{3+}$ in aqueous solution is reported. Linewidths comparable to those of room-temperature solids and Stark splittings which suggest a low-symmetry quasistatic environment are observed.

Physical review. B, Condensed matterOct 1, 1983127 citations

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Mohamed Bouazaoui, B. Jacquier, C. Linarès +1 more

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Journal of Physics Condensed MatterFeb 25, 199117 citations

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N. Bloembergen

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International Conference on Luminescence - 1984Jan 1, 19840 citations

Photon-assisted off-resonance energy transfer between Cr3+ and Gd3+ in GdAlO3

José Luciano Miranda Duarte, Jarbas Caiado de Castro

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Physical review. B, Condensed matterSep 1, 19922 citations

Two-photon absorption in gadolinium ions

B. R. Judd, D R Pooler

Recent observations of two-photon absorption within the configuration 4f 7 of Gd 3+ in LaF 3 have indicated an anomalously high line strength for the transition 8 S 7/2 to 6 P 7/2 compared with 8 S 7/2 to 6 P 5/2 and 8 S 7/2 to 6 P 3/2 . It is shown that the standard expression for the two-photon intensity is unusually small for all three transitions and that a higher-order correction, involving matrix elements of the spin-orbit interaction within the intermediate configuration 4f 6 5d, predominates. The principal term is scalar, implying (in the absence of J mixing by the crystal field) isotropic contributions to the various components of the Delta J=0 transition. The line strengths that have been observed can be accounted for reasonably well without having to invoke variations in the radial integral (4f mod r mod 5d) or inadequacies in the closure approximation. Expressions for the transition matrix elements are given for the general configuration l N .Recent observations of two-photon absorption within the configuration 4f 7 of Gd 3+ in LaF 3 have indicated an anomalously high line strength for the transition 8 S 7/2 to 6 P 7/2 compared with 8 S 7/2 to 6 P 5/2 and 8 S 7/2 to 6 P 3/2 . It is shown that the standard expression for the two-photon intensity is unusually small for all three transitions and that a higher-order correction, involving matrix elements of the spin-orbit interaction within the intermediate configuration 4f 6 5d, predominates. The principal term is scalar, implying (in the absence of J mixing by the crystal field) isotropic contributions to the various components of the Delta J=0 transition. The line strengths that have been observed can be accounted for reasonably well without having to invoke variations in the radial integral (4f mod r mod 5d) or inadequacies in the closure approximation. Expressions for the transition matrix elements are given for the general configuration l N .

Journal of Physics C Solid State PhysicsJan 30, 1982120 citations

Two-photon absorption spectroscopy is used to study f\ensuremath{\rightarrow}f transitions of the

{\mathrm{Gd}}^{3+}

ion in pure

{\mathrm{GdAlO}}_{3}

A comprehensive report and analysis of our observations of numerous parity-allowed direct two-photon transitions within the

4{f}^{7}

configuration of the

{\mathrm{Gd}}^{3+}

ion is presented. The experimental technique is ultraviolet fluorescence detection following optical excitation with a dye-laser beam. Previous results and analyses are extended in three ways. (1) The intensities and polarization dependence of individual Stark components, in addition to integrated multiplet intensities, are reported and analyzed for

{\mathrm{Gd}}^{3+}

:La

{\mathrm{F}}_{3}

. In those cases ($^{8}S_{\frac{7}{2}}\ensuremath{\rightarrow}^{6}P_{\frac{5}{2}},^{6}D_{\frac{9}{2},\frac{3}{2},\frac{5}{2}}$) where a second-order theory of two-photon absorption adequately explains the integrated intensity, it also (with the exception of

^{6}D_{\frac{9}{2}}

) explains the Stark-component intensities. The remaining transitions are anomalously strong, and in some cases violate the angular momentum selection rules $\ensuremath{\Delta}L,\ensuremath{\Delta}J\ensuremath{\le}2$ and exhibit strong anisotropies, in contradiction to the second-order theory. It is shown that introduction of third- and fourth-order contributions involving spin-orbit and/or crystal-field interactions among levels of the

4{f}^{6}5d

configuration, which serve as intermediate states, can account for both the integrated and Stark-component intensities of these transitions. (2) The strong anisotropy observed for the transitions $^{8}S_{\frac{7}{2}}\ensuremath{\rightarrow}^{6}P_{\frac{3}{2}},^{6}I_{J},^{6}D_{\frac{1}{2}}$ in

{\mathrm{Gd}}^{3+}

:La

{\mathrm{F}}_{3}

is explained quantitatively as a polarization-dependent interference between contributions to the intensity which are comparable in magnitude. Interference is destructive for $\stackrel{\ensuremath{\rightarrow}}{E}\ensuremath{\parallel}\stackrel{^}{z}$ and constructive for $\stackrel{\ensuremath{\rightarrow}}{E}\ensuremath{\perp}\stackrel{^}{z}$, creating an order-of-magnitude contrast in the line strength for the two polarizations. (3) A two-photon excitation spectrum of

{\mathrm{Gd}}^{3+}

in aqueous solution is reported. Linewidths comparable to those of room-temperature solids and Stark splittings which suggest a low-symmetry quasistatic environment are observed.

We report here a clear observation of photon-assisted off-resonance energy transfer. Our experiment was carried out in crystals of gadolinium aluminate (

{\mathrm{GdAlO}}_{3}

) doped with chromium ions (

{\mathrm{Cr}}^{3+}

). The observed phenomenon consists of the energy transfer from a

{\mathrm{Cr}}^{3+}

ion, previously excited to the

^{2}

E state (located at about 13.770 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ above the ground state), to a neighbor

{\mathrm{Gd}}^{3+}

ion (which has the first excited state located at about 31.840 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$), with the simultaneous absorption of a photon that energy matches exactly the difference between the gadolinium excited-state energy and the energy supplied by the chromium ion.