Lutetium hardness

Dysprosium, Dy Lutetium, Lu > L. de Boisbaudran G. Urbain 1886 Greek hvanpoaixog, dysprositos, hard to get... 

Selected stability constants for scandium, yttrium, lanthanum, and lutetium are shown in (Table 3) They show a preference for hard donor atoms, as might be expected for the trivalent metals, but complexes with softer donor atoms like nitrogen can be isolated by operating in nonaqueous solvents. 

Lutetium is also a very rare metal, with a world production (as lutetium oxide) of approximately 10 tons per year. One commercial application is known it is used as a P-emitter, (when Lu-176 has been exposed to neutron activation) in the oil refining industry (Emsley 2001). It was used in so-called-bubble memory, a technology for computer memory that has become obsolete, since hard disks have made their rapid substantial advance. It is still used in scintillation crystals for PET-scanners (positron emission scanners). It is used here in the form of cerium-doped Lutetium oxy-orthosilicate (LSO), with the formula Ce2x Lu2(l — x) SiOs, where x is within tire range from approximately 2 x 10 to approximately 3 X 10 (Melcher 1990 Daghighian et al. 1993). 

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