Thulium spectra

Soret and Delafontaine identified holmium in 1878 by examination of its spectrum. The following year, Cleve separated its oxide from Marignac s erbia, a mixture of erbium, holmium and thulium oxides. He named this element Holmium, after his native town Holmia (Stockholm). The metal was produced in 1934 by Klemm and Bommer. 

Thulium displays in minerals an intense UV and blue visible luminescence with a line spectrum near 360 and 450 nm, correspondingly. They are connected with electron transitions from different excited levels D2 and at 360-365 and 450-455 nm. The liuninescence of Tm " is more easily detected in time-resolved spectra with a narrow gate, because it usually has a relatively short decay time. The UV Hne usually has a much shorter decay time compared with the blue line. Different decay times from these levels are evidently connected with nonradiative relaxation due to the presence of high frequency vibrations in the lattice. The best excitation is at 355 nm, which is connected with transition... 

Swedish physicist, astronomer, and spec-troscopist. He mapped the spectra of yttrium, erbium, didymium, lanthanum, scandium, thulium, and ytterbium, and in 1866 wrote a histoncal review of spectrum analysis. He also studied the magnetic properties of iron and iron ores. 

Important scientific and industrial applications for thulium and its compounds remain to be developed. In particular, the photoelectric, semiconductor, and thermoelectric properties of the element and compounds, particularly behavior in the near-infrared region of the spectrum, are being studied. Thulium has been used in phosphors, ferrite bubble devices, and catalysis. Irradiated thulium (169Tm) is used in a portable x-ray unit. 

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. 

The thulium (III) ion exhibits spectrally narrow light emission at about 480 nm. Li and coworkers were the first to use the Tm + ion in OLEDs [65]. They prepared a Tm complex Tm(acac)3(phen) and constructed double-layer cells with structure ITO/PVK/Tm complex/Al. The electroluminescence spectrum of the OLED with drive voltage 10 V and the photoluminescence spectrum with excitation wavelength at 350 nm are shown in Figure 11.29. The emitting intensity of 6.0cdm was achieved when a 16 V forward bias voltage was applied. 

Figure 11.29 Square symbols-the EL spectrum of the device ITO/PVK/Tmcomplex/Al at drive voltage 10 V solid line - the PL spectrum of the Tm(ACAC)3(phen) powder (excitation wavelength 350 nm) [65]. (Reproduced from Synthetic Metals, 104, Z.R. Hong et al., Spectrally-narrow blue light-emitting organic electroluminescent devices utihzing thulium complexes, 165-168, 1999, with permission from Elsevier.)...

Silvery-white, easily worked metal. Hexagonal close-packed structure, d 9.332. mp 1545". The solns of thulium salts show a characteristic absorption spectrum Exner,... 

Initial measurements on thulium iron garnet TmlG, failed to observe all peaks in the spectrum [171], but later data gave values for the internal magnetic fields at the two thulium sites of 1700 and 810 kG at 20 K [172]. The fields are reduced from the free-ion value and that in Tm metal by anisotropic crystal-field and exchange interactions. 

Charge transfer bands result whenever an easily oxidized ligand is bound to a trivalent lanthanide ion which can be reduced to the divalent state or when the ligand is bound to one of the tetravalent ions (J0rgensen, 1970). Such transitions are commonly observed in the spectra of complexes of samarium(III), euro-pium(III), thulium(III), ytterbium(III), and cerium(IV). The position of these bands in the spectrum is markedly dependent on the ligand and the metal ion. For example, in the ions RCU the charge transfer bands for europium(III),... 

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