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Molybdenum-zinc substituted hexaferrites were synthesized by high-energy ball milling and subsequent sintering at different temperatures (1100, 1200, and 1300° C). The samples sintered at 1100° C exhibited good hard magnetic properties, although a decrease in saturation magnetization from 70.2 emu/g for the unsubstituted sample down to 57 emu/g for the sample with x = 0.3 was observed. The drop in saturation magnetization results mainly from the presence of secondary nonmagnetic oxides. The samples sintered at temperatures ≥1200° C showed an improvement in saturation magnetization, and a sharp drop in coercivith. This behavior was associated with the development of the W-type hexaferrite, the particle growth, and possibly the spin reorientation transition from easy-axis to easy-plane.

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In recent times, synthetic organic reactions have gained significant attention as they are becoming a versatile tool in the synthesis of pharmaceuticals, agrochemicals and their intermediates. Sulfamic acid (SA) is an acid catalyst that demonstrated high efficiency in various organic transformations that will be highlighted in this review. These include efforts to develop green approaches using SA catalyst for the CÀ C bond formation reactions and functional group trans-formations, as well as the synthesis of various OÀ and Nheterocyclic compounds and other miscellaneous reactions including multicomponent reactions. The easy recovery (for subsequent reuse) of the catalyst by filtration without the need for solvents is an important advantage of SA catalyst. In this review, SA promoted greener methodologies that were developed and the applicability of these methodologies are addressed.