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The article presents a chemical equation which explains the use of magnetic graphene nanocomposite as a catalyst for hydrogenation of nitroarenes.

Magnetization reversal and exchange coupling are investigated in Pr-Fe-B melt-spun ribbons. In nanocomposite magnets, not only does the coercivity decrease but also magnetization reversal becomes more non-uniform in hard grains. The non-uniform magnetization reversal, resulting in a deterioration of squareness in hysteresis loop and a drop of the maximum Henkel plot value, mainly is caused by random arrangement of easy axes and intergranular soft regions among hard grains even with well exchange coupling between soft-hard grains in these ribbons. It is expected that the uniformity in magnetization reversal could be improved with the perfection of easy axes alignment in anisotropy nanocomposites. [ABSTRACT FROM AUTHOR]

The strain-mediated magnetocapacitance (MC) of 1–3-type vertical ferroelectric–ferromagnetic nanocomposite films epitaxially grown on different cubic substrates is theoretically calculated using the nonlinear thermodynamic theory combined with elastic theory. The dependences of relative dielectric constant and strain sensitivity of permittivity for the ferroelectric film on the in-plane and out-of-plane misfit strains are obtained. Our results show that the MC effect strongly depends on the in-plane misfit strain and ferromagnetic volume fraction in the nanocomposite films. The calculated MC for the BaTiO3–CoFe2O4 nanocomposite film grown on the SrTiO3 substrate is consistent with the experimental result. Furthermore, a giant MC, which is enhanced by 1–2 orders of magnitude than those reported in experiments, can be obtained for the BaTiO3–CoFe2O4 system grown on the MgO substrate near the transition from the aa-phase to the r-phase. Our result provides a new method for the design of multiferroic nanocomposites with colossal MC effect by optimizing the ferromagnetic phase and substrate types to realize their applications in magnetic-field-controlled electric devices, such as magneto-oscillators, magnetovaractors and magnetoelectric sensors. [ABSTRACT FROM AUTHOR]

To find alternative high temperature magnets containing no heavy rare earths for power applications, SmCo5/Fe bulk nanocomposite magnets with enhanced energy density and high thermal stability have been produced by using a ball-milling plus warm-compaction route. Up to 30% of the Fe soft magnetic phase has been added to the composites with grain size <20 nm distributed homogenously in the matrix of the SmCo5 hard magnetic phase. It was observed that the microstructure does not change with temperature up to 500 °C. It is also observed that the thermal stability of bulk nanocomposite samples is closely related to bulk density. Energy products above 11 MGOe have been obtained at 300 °C in fully dense bulk SmCo5/Fe nanocomposite magnets, which is 65% higher than that of a single-phase counterpart at the same temperature. [ABSTRACT FROM AUTHOR]