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In this letter, we report the study of MoS2 crystals after irradiation with a high dose of electrons. A pelletron accelerator was used to irradiate the sample with electrons at an energy of 0.5 MeV. Samples were examined in high resolution electron microscopy. Two main structures were observed: onion layers with fullerene like structure and others with their planes rotated with respect to each other by well-defined angles. We present a calculation showing that relative rotation of the sulphur layers by 3°, 5°, 8°, and 16° basically have the same average energy as the unrotated structure. Therefore rotations of the layers through those angles will be favored. Instability on the structure produced by irradiation will induce rotations on the structure.

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99m Tc generator / Hydrotalcite / Calcined hydrotalcite / Molybdenum Summary. 99 MoO 4 2− sorption behavior on 3 commercial hydrotalcites, produced by Sasol Chemie, was studied through batch experiments. Only one of them showed high sorption capacity. This product, the MG70 was identified by XRD diffraction analysis as hydrotalcite (Mg 6 Al 2 (OH) 16 CO 3 ·4H 2 O), while the other two, MG50 and MG30, were identified mainly as magnesium aluminum hydroxide hydrate, MgAl 2 (OH) 14 ·3H 2 O. Calcined MG70 (CMG70) was used to retain about 298.17 ± 8.3 mg of 99 Mo-MoO 4 2− (MG70-99 MoO 4 ). When this material was packed in a glass column, the generated 99m Tc was eluted by using NaCl or HNO 3 aqueous solutions. Saline solutions eluted 99m Tc with considerable amounts of 99 Mo while 0.1 M HNO 3 eluted 99m Tc together with a such small amount of 99 Mo that the 99 Mo µCi/ 99m Tc mCi ratios are close to the value recommended by the American Pharmacopeia.