Publications by authors named "Alexander Birkel"

We present a rapid microwave-assisted solid-state approach to prepare complex platinum-group metal oxides with the formula La2BaMO5 (M = Pd, Pt). While conventional furnace-based preparations of these compounds take several days and often require oxidizing conditions, the microwave-assisted pathway enables the target compounds to be obtained with high phase purity in about 20 min of reaction time in air without the multiple regrindings that are required of conventional solid-state synthesis. These complex oxides are stable in various atmospheres up to 1000 °C unlike the simple noble metal oxides, which are reduced even at room temperature.

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We present a rapid microwave-assisted sol-gel approach to Pd-substituted LnFeO3 (Ln = Y, La) for applications in C-C coupling reactions. These materials could be prepared in household microwave ovens in less than 15 minutes of reaction time with the final materials displaying well-defined structure and morphology. Phase evolution was studied using time-dependent microwave heatings and then compared with the results obtained from thermogravimetric analyses.

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Structural intricacies of the orange-red nitride phosphor system La(3-x)Ce(x)Si6N11 (0 < x ≤ 3) have been elucidated using a combination of state-of-the art tools, in order to understand the origins of the exceptional optical properties of this important solid-state lighting material. In addition, the optical properties of the end-member (x = 3) compound, Ce3Si6N11, are described for the first time. A combination of synchrotron powder X-ray diffraction and neutron scattering is employed to establish site preferences and the rigid nature of the structure, which is characterized by a high Debye temperature.

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Reaction pathways to SnO(2) nanomaterials through the hydrolysis of hydrated tin tetrachloride precursors were investigated. The products were prepared solvothermally starting from hydrated tin tetrachloride and various (e.g.

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