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Ferromagnetic zinc ferrite nanocrystals at ambient temperature were synthesized via the thermal decomposition of metal-surfactant complexes. Characterization measurements including transmission electron microscopy and X-ray diffraction were performed for as-synthesized ZnFe 2 O 4 particles. The sample has a relatively narrow size distribution with an average particle size of 9.8 ( 0.2 nm and standard deviation of 30%. The assynthesized zinc ferrite nanocrystals are superparamagnetic at room temperature with a blocking temperature T B ) 68 ( 2 K and a saturation magnetization M S ) 65.4 emu‚g -1 at T ) 10 K, which are caused by the change in the inversion degree of the spinel structure. A coercive field of H C ) 102 ( 5 Oe in the blocked state indicates small particle anisotropy, although evidence of surface spin canting was inferred from magnetization data in the as-synthesized ZnFe 2 O 4 nanocrystals. Our results demonstrate that magnetic properties of magnetic particles can be largely modified by just changing particle size, which might be a useful way to design novel magnetic materials.

Dry reforming of methane has gained significant interest over the years. A novel reforming technique with great potential is plasma technology. One of its drawbacks, however, is energy consumption. Therefore, we performed an extensive computational study, supported by experiments, aiming to identify the influence of the operating parameters (gas mixture, power, residence time and "frequency") of a dielectric barrier discharge plasma on the conversion and energy efficiency, and to investigate which of these parameters lead to the most promising results and whether these are eventually sufficient for industrial implementation. The best results, in terms of both energy efficiency and conversion, are obtained at a specific energy input (SEI) of 100 J cm À3 , a 10-90 CH 4 -CO 2 ratio, 10 Hz, a residence time of 1 ms, resulting in a total conversion of 84% and an energy efficiency of 8.5%. In general, increasing the CO 2 content in the gas mixture leads to a higher conversion and energy efficiency. The SEI couples the effect of the power and residence time, and increasing the SEI always results in a higher conversion, but somewhat lower energy efficiencies. The effect of the frequency is more complicated: we observed that the product of frequency (f) and residence time (s), being a measure for the total number of microdischarge filaments which the gas molecules experience when passing through the reactor, was critical.For most cases, a higher number of filaments yields higher values for conversion and energy efficiency. To benchmark our model predictions, we also give an overview of measured conversions and energy efficiencies reported in the literature, to indicate the potential for improvement compared to the state-ofthe art. Finally, we identify the limitations as well as the benefits and future possibilities of plasma technology. † Electronic supplementary information (ESI) available: The ESI contains (a) an overview of the detailed experimental and computational results, used for the model validation; as a function of the CH 4 -CO 2 ratio, the residence time and the SEI. (b) All graphs and a more extensive description of the inuence regarding gas ratio in the entire range of conditions. See