Rapid Microwave Synthesis of the Iron Arsenides NdFeAsO and NdFe₀.₉Co₀.₁AsO

The future of iron pnictide superconductors in technology is still undecided. While these materials are now known to possess high critical temperatures and critical magnetic fields processing methods for these materials are still in their infancy. Recently we have been investigating possible ways to speed up the synthetic process for obtaining polycrystalline iron arsenide superconductors and other transition metal pnictides. Here we report the synthesis of NdFeAsO and NdFe₀.₉Co₀.₁AsO in less than one hour total exposure to microwave radiation using a secondary microwave susceptor to surround the reaction ampoule. Magnetic susceptibility and electronic resistivity measurements reveal the Co doped sample to be of high quality with a narrow transition range

We bleed orange, green, & blue: rapid microwave synthesis of advanced pigments

This work prepared YInMnO3, YCuTiO3, and YInFeO3 solid state pigments via microwave synthesis. The microwave-prepared pigments contain optical and structural properties similar to their furnace homologues. Overall synthesis times for each pigment have been significantly reduced via microwave synthesis, while keeping the same relative phase purity as solid-state.The compound of interest at the conception of this research project was YInMnO3, a new bright blue inorganic pigment discovered by Mas Subramanian in 2009.1 The pigment’s unique reflective properties in the infrared region of light give this compound potential as a passive heat reducer in cool roofing. The project was conceived with a desire to find alternate routes to synthesis of this promising blue pigment. CuTiO3 and YInFeO3,2,3 other hexagonal pigments with metal ions in the same trigonal bipyramidal coordination, were made with similar experimental parameters after successful synthesis of YInMnO3 in the microwave. Previous research has identified microwave-active elements and compounds that heat up rapidly when exposed to microwave energy. Undergraduate student Casey Young profiled various susceptors in the microwave to determine a working susceptor with the capability of heating to 1300 degrees Celsius (the literature temperature required to synthesize YInMnO3). Thermal profiles were gathered for several susceptors, collecting temperature readings at various power levels and heating interval lengths. The susceptors tested were tungsten oxide, activated and non-activated manganese dioxide, silicon carbide, cupric oxide, activated carbon mesh, and granular carbon slug. Reusability and maximum temperature were both significant limitations. The susceptor that proved most optimal for synthesis was carbon slug 6-8 mesh, which rose to 1350 degrees Celsius and was reusable after successive heatings. Casey Young determined the optimal parameters for microwave synthesis, including crucible type, crucible dimensions, type of susceptor, amount of susceptor, microwave power level, duration of heating intervals, and amount of heating intervals necessary for successful synthesis. After Casey Young determined ideal microwave synthesis conditions, the student ran several trials to synthesize YInMnO3 and YCuTiO3 and analyzed phase-purity via XRD to find optimal heating time. Using the parameters outlined by Casey Young, undergraduate student colleague Omar Rachdi ran trials of YInFeO3 to find optimal heating time for synthesis. Casey Young and Omar Rachdi then constructed a poster for CUE 2013 and presented to the general public on May 15th, 2013. The findings of this project are significant because it shows alternative synthesis routes for YInMnO3 and other pigments of similar structure. The conventional synthesis of YInMnO3 in a furnace requires three full days of heating; microwave synthesis of this compound was shown to reduce the synthesis time to under 2 hours. This reduced heating time holds potential to reduce production cost of YInMnO3, giving this environmentally beneficial pigment greater economic potential. 1. Smith, A. E. et al. Mn 3+ in Trigonal Bipyramidal Coordination: A New Blue Chromophore. J. Am. Chem. Soc. 131, 17084–17086 (2009). 2. Smith, A. E., Sleight, A. W. & Subramanian, M. A. Synthesis and properties of solid solutions of hexagonal YCu0.5Ti0.5O3 with YMO3 (M = Mn, Cr, Fe, Al, Ga, and In). Mater. Res. Bull. 46, 1–5 (2011). 3. Jiang, P., Li, J., Sleight, A. W. & Subramanian, M. A. New Oxides Showing an Intense Orange Color Based on Fe3+ in Trigonal-Bipyramidal Coordination. Inorg. Chem. 50, 5858–5860 (2011)

CUE 2013 poster - Casey Young & Omar Rachdi.pdf

This work prepared YInMnO3, YCuTiO3, and YInFeO3 solid state pigments via microwave synthesis. The microwave-prepared pigments contain optical and structural properties similar to their furnace homologues. Overall synthesis times for each pigment have been significantly reduced via microwave synthesis, while keeping the same relative phase purity as solid-state.Keywords: YCuTiO3, Trigonal, Bipyramidal, Coordination, Rapid, Synthesis, Microwave, YInFeO3, Blue, YInMnO3, Pigmen

CUE 2013 poster - Casey Young & Omar Rachdi.ppt

This work prepared YInMnO3, YCuTiO3, and YInFeO3 solid state pigments via microwave synthesis. The microwave-prepared pigments contain optical and structural properties similar to their furnace homologues. Overall synthesis times for each pigment have been significantly reduced via microwave synthesis, while keeping the same relative phase purity as solid-state.Keywords: YInMnO3, Pigment, Microwave, Rapid, Bipyramidal, YInFeO3, Blue, YCuTiO3, Coordination, Synthesis, Trigona

A regionally based precision medicine implementation initiative in North Africa:The PerMediNA consortium

International audiencePrecision Medicine is being increasingly used in the developed world to improve health care. While several Precision Medicine (PM) initiatives have been launched worldwide, their implementations have proven to be more challenging particularly in low- and middle-income countries. To address this issue, the “Personalized Medicine in North Africa” initiative (PerMediNA) was launched in three North African countries namely Tunisia, Algeria and Morocco. PerMediNA is coordinated by Institut Pasteur de Tunis together with the French Ministry for Europe and Foreign Affairs, with the support of Institut Pasteur in France. The project is carried out along with Institut Pasteur d’Algérie and Institut Pasteur du Maroc in collaboration with national and international leading institutions in the field of PM including Institut Gustave Roussy in Paris. PerMediNA aims to assess the readiness level of PM implementation in North Africa, to strengthen PM infrastructure, to provide workforce training, to generate genomic data on North African populations, to implement cost effective, affordable and sustainable genetic testing for cancer patients and to inform policy makers on how to translate research knowledge into health products and services. Gender equity and involvement of young scientists in this implementation process are other key goals of the PerMediNA project.In this paper, we are describing PerMediNA as the first PM implementation initiative in North Africa. Such initiatives contribute significantly in shortening existing health disparities and inequities between developed and developing countries and accelerate access to innovative treatments for global health