Erbium configurations

Erbium is a chemical element. Its ground state electronic configuration is [Xe]4f12 6s2. Natural erbium is a mixture of six stable isotopes. Monazite... 

Erbium(III) with f11 configuration has 17 multiplet terms with 41 levels due to spin-orbit coupling. The J energy levels are more separated than in Nd3+. The energy level diagram... 

Lanthanide elements (referred to as Ln) have atomic numbers that range from 57 to 71. They are lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). With the inclusion of scandium (Sc) and yttrium (Y), which are in the same subgroup, this total of 17 elements are referred to as the rare earth elements (RE). They are similar in some aspects but very different in many others. Based on the electronic configuration of the rare earth elements, in this chapter we will discuss the lanthanide contraction phenomenon and the consequential effects on the chemical and physical properties of these elements. The coordination chemistry of lanthanide complexes containing small inorganic ligands is also briefly introduced here [1-5]. 

The particular case of yttrium is very useful to gain a deeper insight into this effect. Yttrium presents strong chemical similarities with lanthanides and its ionic radius (1.075 A) make it close to dysprosium (1.083 A) or erbium (1.062 A) on the other hand its electronic configuration (4f ) is identical to that of lanthanum. Plotting the variation of / vs the... 

The lutetium hahdes (except the fluoride), together with the nitrates, perchlorates, and acetates, are soluble in water. The hydroxide oxide, carbonate, oxalate, and phosphate compotmds are insoluble. Lutetium compounds are all colorless in the solid state and in solution. Due to its closed electronic configuration (4f " ), lutetium has no absorption bands and does not emit radiation. For these reasons it does not have any magnetic or optical importance, see also Cerium Dysprosium Erbium Europium Gadolinium Holmium Lanthanum Neodymium Praseodymium Promethium Samarium Terbium Ytterbium. 

The cubane structure [M4(m3-OR)4] (Fig. 4.6) is favoured by the alkali metal tertiary butoxides (M = K, Rb, Cs) and thallium(i) alkoxides, and also related species such as [Me4Zn4(/ t-OMe)4]. Another common tetranuclear structure [M4(jti-OR)6(OR)6] (Fig. 4.7) involves one central octahedral metal bridged to three tetrahedral metals in a chiral configuration (D3). Crystalline aluminium isopropoxide was the first example established to have this structural type. ° Interestingly in the heterometallic complex [ErAl3(OPr )i2] the central position is occupied by the erbium ion in a distorted trigonal prismatic configuration. ... 

F ure 17-10. Sketch of the setup used to measure optical properties of a sol-gel waveguide doped with erbium/ytterbium ions. Different pigtailed laser diodes and dfferent output coupling configurations may be mixed, in order to perform specific measurements. 

The most glaring discrepancy quoted at the begiiming of this section is the case of the H(2)ii/2 level of triply ionized neodymium. It persisted for a long time in spite of clear experimental evidence (see for instance Caro et al. 1981). Faucher and Garcia (1988) and Faucher et al. (1989a,b) showed that the anomaly touched the rank-four crystal field only they suspected that it concerned twin levels only and proposed an empirical rule to take it into account for any neodymium compound within the classical one-electron cfp fitting. The same type of correction applies to the H(2)n/2 level of trivalent erbium in the complementary 4f configuration (Moune et al. 1991). 

Phosphorescence and Fluorescence Many ceramics phosphoresce and fluoresce. These ceramics find applications in fluorescent lights, oscilloscope screens, television screens, electroluminescent lamps, photocopy lamps, and lasers. Lasers include tungstates, fluorides, molybdates, and garnet compositions doped with chromium, neodymium, europium, erbium, praseodymium, and so on. Ceramic phosphor is Ca5(P04)3(Cl,F) or Sr5(P04)3(Cl,F) doped with Sb and Mn. Figure 1.9 shows some configurations of fluorescent lights. 

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