Synthesis,crystal structure,magnetism, and absorption spectra of A2UX5 Type Halides (A = K,Rb; X = Cl,Br, I) |
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Authors: | Karl Krmer Hans U Güdel Gerd Meyer Thorsten Heuer Norman N Edelstein Bernd Jung Lukas Keller Peter Fischer Eugeniusz Zych Janusz Drozdzynski |
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Institution: | Karl Krämer,Hans U. Güdel,Gerd Meyer,Thorsten Heuer,Norman N. Edelstein,Bernd Jung,Lukas Keller,Peter Fischer,Eugeniusz Zych,Janusz Drozdzynski |
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Abstract: | The ternary uranium(III) halides A2UX5 (A = K, Rb; X = Cl, Br, I) have been prepared from the binary components AX and UX3 in sealed tantalum containers. According to their Guinier X-ray powder patterns, they all crystallize with the K2PrCl5/Y2HfS5 type of structure. Lattice constants for ambient temperature are reported. Single-crystal structure refinemens were undertaken for K2UI5 and Rb2UCl5. Magnetic susceptibility data were recorded with a SQUID magnetometer from liquid helium to room temperature. One-dimensional (intrachain) and three-dimensional antiferromagnetic ordering occur at low temperatures dependent upon the U3+? U3+ distance. Absorption spectra were recorded between 4 000 and 28 000 cm?1. They show f—f transitions typical for U3+ and, depending on the halide, very strong f—d transitions above 14 000 to 15 000 cm?1, respectively. |
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Keywords: | Alkali uranium halides A2UX5 (A = K Rb X = Cl Br I) preparation crystal structure magnetic susceptibility UV-Vis spectra |
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