Intercalation von Stickstoff und Wasserstoff Sr2N sowie ortsabhängige Feststoffchakterisierung mit Laserablation (English shop)

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The structures of the alkaline earth metal subnitrides (EA2N) of calcium, strontium and barium, with their layered arrangement of EA6N octahedra, permit intercalation reactions. The redox intercalation of nitrogen into Sr2N was investigated on single crystals. Only through a drastic increase of the reaction gas pressure compared with the reactions on microcrystalline samples did the intercalation of diazenide ions into the crystals to give Sr4N3 and SrN become possible.

For an analogous intercalation of hydrogen into Sr2N, the reaction conditions could be optimised such that phase-pure strontium nitride hydride (Sr2N)H, and the deuteride (Sr2N)D respectively, was obtained for the first time. By means of intercalation reactions with Sr2N crystals it could be shown that the intercalation process, recognisable by the distinct colour change from black to amber, proceeds from the outside inwards.

Laser ablation in combination with an ICP mass spectrometer (LA-ICP-MS) was used as the method for spatially resolved analysis. Quantification strategies described in the literature were examined for their applicability to the given problem. With the spatially resolved analysis of single crystals it could be shown that the intercalation of nitrogen into the crystals proceeds continuously from the edges towards the centre of the crystal.