Computer modelling of thorium doping in LiCaAlF6 and LiSrAlF6: application to the development of solid state optical frequency devices
This paper describes computer modelling of thorium doping in crystalline LiCaAlF6 and LiSrAlF6. The study has been motivated by the interest in using these materials as hosts for 229Th nuclei, which are being investigated for use as frequency standards. The dopant sites and form of charge compensation are obtained; this information is essential for the further development and optimization of these devices.
Zur Kenntnis binärer Fluoride des ZrF4-Typs: HfF4 und ThF4
Die binaren Fluoride MF4 (M = Hf, Th) wurden erstmals in Form von farblosen Einkristallen, monoklin mit a = 1172,5 pm, b = 986,9 pm, c = 763,6 pm und β = 126,15°, R = 6,7% bzw. RW = 7,24% (Hf), a = 1304,9 pm, b = 1112,0 pm, c = 853,8 pm und β = 126,30°, R = 4,48% bzw. RW = 4,28% (Th), Raumgruppe C2/c–C (Nr. 15), Z = 12 (Vierkreisdiffraktometer Siemens AED 2, MoKα, 1040 von 1050 Io(hkl)) (Hf), 1446 von 1446 Io(hkl) (Th), dargestellt und untersucht. 
 
 
 
Der Madelunganteil, MAPLE, sowie „Mittlere Fiktive Ionenradien, MEFIR”, und „Effektive Koordinationszahlen, ECoN”, wurden berechnet und diskutiert. 
 
 
 
On Binary Tetrafluorides of the ZrF4 Type 
 
 
 
For the first time colourless single crystals MF4 (M = Hf, Th), monoclinic with a = 1172.5 pm, b = 986.9 pm, c = 763.6 pm and β = 126.15°, R = 6.7% respectively RW = 7.24% (Hf), a = 1304.9 pm, b = 1112.0 pm, c = 853.8 pm and β = 126.30°, R = 4.48% respectively RW = 4.28% (Th), Spacegrp. C2/c–C (Nr. 15), Z = 12 (Fourcircle-Diffraktometer Siemens AED 2, MoKα, 1040 von 1050 Io(hkl)) (Hf), 1446 von 1446 Io(hkl) (Th) have been obtained. 
 
 
 
The “Madelungpart of Lattice Energy, MAPLE”, “Mean Fictive Ionic Radii, MEFIR”, and “Effective Coordination Numbers, ECoN”, were calculated and discussed.
Industrial inorganic pigments
General Chemical and Physical Properties Behavior of Pigments in Binders White Pigments Titanium Dioxide Zinc Sulfide Colored Pigments Oxides and Hydroxides Cadmium Pigments Bismuth Pigments Ultramarine Pigments Iron Blue Pigments Carbon Black Properties Production Processes Specialty Pigments Magnetic Pigments Anticorrosive Pigments Luster Pigments Transparent Pigments.