Absorption spectra erbium

For our purposes, it is interesting to note that the perovskite ErAlo.9Cro.1O3 emits the continuous spectrum of Cr(III) without the red and green Er(III) bands in spite of the fact that the aqueous solution has e of erbium(III) at 5230 A equal to 3.2 to be compared with a-tenth of e, 1.3 of chromium(III) at 5750 A. The absorption spectrum of the nitrate solution is even more striking in a spectroscope, because the transitions of Er(III) are so much narrower. Quite generally, Cr(III) seems to be very effective to prevent narrow band luminescence of the lanthanides. 

Four rare-earth elements (yttrium, ytterbium, erbium, and terbium) have been named in honor of this village. A year later, the Swedish chemist Lars Fredrik Nilson (1840-1899), discovered another element in "erbia" and he named it scandium (Sc) in honor of Scandinavia. At the same time, Nilson s compatriot, the geologist and chemist Per Theodor Cleve (1840-1905) succeeded in resolving the "erbia" earths yet another step further, when he separated it into three components erbium, "holmium" (Flo) and thulium (Tm). The name "holmium" refers to Stockholm (Qeve s native city) and had been independently discovered by the Swiss chemists Marc Dela-fontame (1838-1911) and Jacques-Louis Soret (1827-1890), who had coined the metal element X on the basis of its absorption spectrum. 

Porphyrin molecules form stable complexes with lanthanide ions, these complexes have intensive absorption in a visible range of spectrum. Erbium, ytterbium and neodymium complexes are characterized by a 4f-luminescence in near IR-range of spectrum [1]. The most studied complexes with porphyrins are ytterbium complexes since Yb has smaller ionic radius in comparison with lanthanum (radius of Yb ion is 1.01 A), which determines higher stability of these metallocomplexes. Distinctive feature of Yb porphyrin complexes is a characteristic narrow and rather intensive luminescence band located in the IR-range at 975-985 nm, in so-called therapeutic window of tissue transparency. ... 

Marignac investigated erbium precipitates and found that they were not homogeneous. Two elements were present. One formed red salts with a characteristic absorption spectrum, while compounds of the other element were colorless. The element with the red color kept the name erbium, the other he called ytterbium. The discovery was made in 1878 and separation was possible by addition of hyposulfurous acid to chloride solutions. The erbium precipitated but not the ytterbium. The two elements erbium and ytterbium also appeared to be mixed, and research had to continue. 

The far-infrared and visible spectra of erbium oxide have been observed by Bloor et al. (1970) about the antiferromagnetic state at 3.4 K. The complex spectra can be interpreted in terms of ions on two nonequivalent sites. The changes in the visible absorption spectrum, together with changes in phonon frequencies, are attributed to the presence of the exchange fields and a magnetostrictive expansion of the crystal lattice in the ordered state. 

Yttrium is one of the most abundant rare earth elements and its purification is easily accomplished. Yttrium fractions from a bromate series are freed from dysprosium, holmium, and erbium by fractional precipitation with ammonia, K2OO4, or NaNC>2. The latter is probably the most effective. Yttrium salts give no absorption lines ini the viable portion of the spectrum, consequently the removal of holmium and erbium is easily observed by the direct vision spectroscope. 

Photoluminescence excitation (PLE) spectroscopy was carried out at 77K on oxidized porous silicon containing iron/erbium oxide clusters. The novel PLE spectrum of the 1535 nm Er PL band comprises a broad band extending from 350 to 570 nm and very week bands located at 640, 840, and 895 nm. The excitation at wavelengths of 400 - 560 nm was shown to be the most effective. No resonant PLE peaks related to the direct optical excitation of Er by absorption of pump photons were observed. The lack of the direct optical excitation indicates conclusively that Er is in the bound state and may be excited by the energy transfer within the clusters. 

A new class of polymetallic organolanthanide polyhydride complexes was found by W.J. Evans et al. (1982b). Dicyclopentadienyl-tert-butyl erbium tetrahydrofur-anate decomposes in toluene in the presence of Uthium chloride within ten hours at room temperature with formation of 2-methylpropane, 2-methylpropene and a pink compound, which shows a broad absorption in the infrared spectrum between 1250 and 1200 cm for the j (ErH). A single crystal X-ray structural determination of a pink prismatic crystal shows cation-anion pairs with three dicyclopentadienyl... 

In order to restore the prompt negative fuel temperature coefficient, erbium was added at about 1.5 weight-%. The attached Figure 2 shows the absorption cross section for 167-Er with its two resonance peaks at about 0.4 and 0.6 eV. As fuel temperature increases, the thermal spectrum shifts towards high energy and more neutrons are absorbed in the Er peaks, thus giving a negative reactivity effect. 

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