Dysprosium transitions

A further strategy to achieve white emission uses rare-earth complexes. For example, a dysprosium complex (245) emits two band emissions a yellow band (580 nm) corresponding to the 4F9/2 —> 6Hi3/2 transition and a blue band (480 nm) corresponding to 4F9/2 — 6H15/2 transition of Dy3+ ion in the complex. Li et al. reported Dy-complex white emission OLEDs of a structure of ITO/PVK Dy complex/Mg Ag device [276], Figure 3.13 shows the PL and EL emission spectra of such a complex and its device, respectively. 

Dysprosium activated minerals have liuninescence in the visible part of the spectrum. The spectra of Dy + in minerals are mainly characterized by narrow fines near 480 and 575 nm, accompanied by the weaker ones near 660 and 752 nm corresponding to transitions from level F j2 to the levels of multiplets Hj and (Tarashchan 1978). Consequently, the spectra are not changed with delay time and excitation energy and all luminescence fines of Dy " are characterized by decay time. The best excitation at 350 nm is connected with 4/-4/ ffi5/2- G7 2 transition. Such liuninescence is detected in... 

Similar results were obtained with erbium, dysprosium, and chromium vapors (104, 115). However, on deuterolysis, most transition metal cocondensates afforded mainly unlabeled propene with only two traces of propane and hexanes (104, 107, 110). The differing reactions of metal vapors with propene were interpreted in terms of a change in the [Pg.60]

Lanthanide series Lanthanides are silvery metals with relatively high melting points. Because there is so little variation in properties among inner transition metals, they are found mixed together in nature and are extremely hard to separate. The name of one lanthanide, dysprosium, comes from a Greek word meaning hard to get at. Lanthanide ores were first mined in Ytterby, Sweden. Which four elements are named for this town ... 

More recently, D. Gatteschi et al. have reported on a dysprosium-nitronyl nitroxide ID compound with interesting dynamic properties [76]. Their work illustrates nicely how presently coordination chemistry can modulate a known system [Dy(hfac)3NITEt] [77-80] (with hfac hexa-fluoroacetylacetonate and NITEt 4 -ethyl-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide) to achieve fine control of the physical properties. [Dy(hfac)3 NITEt] is composed of alternating chains of Dy(hfac)3 units and NITEt radicals. This compound displays a transition to a three-dimensional mag-... 

Dysprosium ions Dy3+ can also be populated by direct absorption in the near U.V. part and blue part of the spectrum, or by energy transfer from U02+. The radiative transitions probabilities and branching ratios of Dy for tellurite and phosphate glasses have been calculated and measured51 and the corresponding values are given in Table 3. 

The lifetimes we measured for these transitions are given in Table V together with those measured by Hotop and Marek( 2.) and by Gustavsson et al. 0 The results are in good agreement. The extensive intensity and energy level data available for dysprosium were used to obtain the branch-... 

Figure 14. Structure of the 5988.56-A line of neutral dysprosium (b) spectrum with mass spectrometer set to detect dysprosium-161 photoions (c) spectrum with mass spectrometer set to detect dysprosium-163 photoions (d) photoionization spectrum without mass selection. The strongest two peaks in (d) correspond to dysprosium-162 and dysprosium-164 transitions (11).

The band intensities of the dysprosium and europium complexes are fairly similar except for the acetylacetonate (acac) adducts. The assignments for the two ion emission bands observed for the dysprosium complexes are F9/2- Hi5/2 at 480 nm and Fq/2- His/2 at 572 nm (21). For many other dysprosium complexes, a band assigned to the F9/2- Hii/2 transition was also reported at approximately 650 nm (5, 16). Second-order scatter radiation from the excitation source which occurs in this region prevented observation of this transition. The europium complexes have only two available resonance levels, Dq and Di (8, 9, 22). For the appropriate assignments for the observed bands, see Table I. The Do- F2... 

Of the other lanthanides, europium(III) chloride, an / ion, and terbium(III) chloride, an / ion, have been reported to fluoresce weakly in dimethylformamide solution [16]. The chloride and sulfate salts of samarium(III), an / ion, of gado-linium(III), an f" ion, and of dysprosium(III), an/ ion, are also reported to luminesce weakly in solution [16]. All five of these lanthanides give rise to weak lines which have been assigned to/->-/transitions. 

Cerium, Praeseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutecium, These are the transition elements, and are also called the Lanthanides. Actinium... 

Dysprosium. Large axial anisotropy confines the moments on Dy to the basal plane. Between Jn = 178 K and 7c = 85K, a helical AFM spin structure is present. The helix angle decreases with lower temperature. At 7c, an orthorhombic distortion of the hep lattice occurs and the transition into the FM state is of first order. The spins all have the same magnitude and all point along the orthorhombic a axis, so this is a simple FM structure. 

At ambient conditions, dysprosium is in hep structure and the hep Sm-type phase transition is reported starting at 7 GPa at ambient temperature. The phase transformation from Sm-type dhep, another hexagonal packed stmcture, is reported to be around 17 GPa. Above 42 GPa, dhep phase is shown to transform to the dfee phase hR24 phase) proposed by Hamaya et al. (1993). It should be noted that the stmcture of this dfee phase has also been claimed as orthorhombic Cmmm by Shen et al. (2007). The dfee phase is observed between 42 and 80 GPa. Beyond 82 2 GPa, a phase transition was observed that was attributed to a monoclinic (C2/m phase). It has been... 

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