Thulium crystal structure

The compounds 52-54 can be isolated in the form of intensely colored, highly air- and moisture-sensitive crystals. X-ray crystal structure analyses have been carried out on the derivatives 52n and 53p. Figure 16 shows the molecular structure of the thulium derivative 52n [71]. 

The materials derived from YBa2Cu307 by replacing yttrium with other rare earth elements (lutetium, ytterbium, thulium, erbium, hohnium, dysprosium, gadolinium, europium, samarium, neodymium, lanthanum) are also superconductors, with r, s of 88 to 96 K. The crystal structures of RBa2Cu307 are almost the same as those of YBa2Cu307. The lattice constant is slightly different for the different ionic radii of the rare earth elements, and yet their chemical and physical properties are almost the same as those of YBa2Cu307. 

Treatment of thulium diiodide with substituted phospholide and arsolide salts afforded stable bis(phospholyl)- and bis(arsolyl)thulium(ll) complexes (Scheme 201) as green solids, that were characterized by multinuclear NMR and X-ray crystal structures. The latter clearly revealed the beneficial effects of the steric and electronic properties of crowded phospholyl and arsolyl ligands for the stabilization of divalent thulium.727 Several other homoleptic samarium(ll) and thulium(n) phospholyl sandwich complexes containing the 2,5-di-/-butyl-3,4-dimethylphospholide (=dtp) or 2,5-bis(trimethylsilyl)-3,4-dimethylphospholide (=dsp) ligand have been synthesized and structurally characterized. X-ray studies revealed that [Sm(dtp)2]2 and [Sm(dsp)2]2 are both dimeric in the solid state due to... 

The structural phase transitions in thulium have been studied to 195 GPa (Montgomery et al., 2011). The lanthanide crystal structure sequence, hep Sm-type dhep dfee, is observed below 70 GPa. It is to be noted that the pure/cc phase is not seen in this study. The hexagonal hR24 phase (Montgomery et al., 2011) and orthorhombic Cmmm (Pravica et al., 2006) are used... 

Other exponential contributions to the relaxation rates of Ce +, Nd " " ions are explained naturally from the same standpoint. It seems reasonable to associate the contributions Tj (X exp(-A /kBT) with 4 = 18-19cm with an influence of the thulium ions of the first coordination sphere on the impurity lanthanide ions. An impurity ion distorts the crystal field at a distance of 3.7 A so strongly, that the thulium doublet state is split by approximately 20cm . In fact, there already appears a purely singlet Stark structure of energy levels in the low-symmetry crystal field. The distinction of 4 values for different lanthanide ions ean easily be coimected with the distinction of differences between the ionic radii of impurities and the ionic radius of the host thulium ion. The difference is... 

The temperature dependence of the quadrupole splitting of Tm in TmES yielded an estimate of the values of the CEF parameters for the Tm ion in the ethylsulfate structure. Since optical absorption spectroscopy had previously furnished estimates of the four parameters needed to characterize the CEF in this structure [Wong and Richman (1961)], their determination in this case provided a valuable cross-check on the validity of the method which has been outlined in section 2.1.3. The experiments also revealed a substantial shielding of the 4f electrons from the crystal field, as has been described for the case of thulium metal in section 2.1.3. 

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