Structure and Spectroscopy of Selected Lanthanide Compounds with Coordination Number from 9 to 6

Abstract

The lecture deals with a group of lanthanide compounds in which some structural factors influence, in a special way, spectroscopic properties of the systems under investigation. The following systems were chosen: three with polymeric structure, two of the dimer type, one a pseudo-dimer system with coordination number (C.N.) = 7, and an octahedral compound of LnL 6 type. The crystal structures of the systems under consideration will be shown, their absorption and excitation spectra will be presented and confronted with X-ray data. Radiative and nonradiative processes will be considered and the role of cooperative interactions analyzed. Some aspects of dynamics in solids will be done, too.

Optical behaviour of praseodymium-doped and praseodymium/ytterbium-co-doped double phosphates

“…The oscillator strength of all transitions increases with increasing concentration but not linearly. An effect similar to this was reported by Legendziewicz [19,20] and also was observed for neodymium molybdate and tungstate as results of cooperative interaction [18,19]. The Table 1 presents oscillator strength values for Na 3 Pr(PO 4 ) 2 and Na 3 Lu(PO 4 ) 2 :Pr 3+ 5%, Yb 3+ 2% samples calculated from experimental data.…”

Design of LaPO4:Nd3+ materials by using ionic liquids

“…features site symmetry such as O h and D 4h , the intensities of two transitions: the hypersensitive 4 I 9/2 → 4 G 5/2 , 2 G 7/2 and the 4 I 9/2 → 4 F 7/2 , 4 S 3/2 , 4 I 9/2 → 4 F 5/2 , 2 H 9/2 ones in IR region are about one half of those of the 4 I 9/2 → 4 G 5/2 , 2 G 7/2 transition, while in low symmetry environments the ratio is significantly higher [28]. According to these rules it is possible to conclude that system under investigations exhibits quite low symmetry because the intensities of two transitions in the IR region are comparable and even higher than for the 4 I 9/2 → 4 G 5/2 , obey the J = 2, L = 2 selection rules are the most sensitive to the lanthanide ion environment, and are commonly referred to as hypersensitive.…”

Synthesis, optical and magnetic properties of homo- and heteronuclear systems and glasses containing them

“…Recently, polymeric (one-and two-dimensional) and dimeric lanthanide as well as heteronuclear (lanthanide and transition metal) compounds have attracted considerable interest.1h11 This is motivated by the e †ect of the dimensionality of the polymeric chains on both the optical and magnetic properties and the applications of such materials.12 Previously, we reported the X-ray, optical and magnetic properties of a series of polymeric lanthanide trichloroacetates and their heteronuclear (Cu2`: Ln3`) analogues.10,13h20 Their EPR and electronic spectra show LnÈCu and LnÈLn interactions in the chains. 11,15,17,20 Two other types of glutarates were obtained by us earlier21,22 and X-ray as well as selected spectral data were analysed. Now we have made an e †ort to synthesize a new type of polymeric compound also incorporated in silica glass and to analyse its optical and magnetic properties.…”