FERRITE SINTERED MAGNET, METHOD FOR PRODUCING THE SAME AND MAGNET ROLL AND NON-RECIPROCAL CIRCUIT E

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PROBLEM TO BE SOLVED : To provide a novel, high-performance ferrite sintered magnet which has a higher Br, a higher degree of orientation and a higher HcJ, compared to those of conventional ones, a method for producing the same, and a high-performance magnet roll and a non-reciprocal circuit element using the same. SOLUTION : The method is for producing the ferrite sintered magnet which has an M-type ferrite structure, essentially comprises Ca, an R element, Ba, Fe and Co and has a composition represented by the formula : Ca1-x-yRxBayFe2n-zCoz (atomic ratio) [wherein (1-x-y), x, y and z are contents of Ca, R element, Ba and Co, respectively; n is the molar ratio; and x, y, z and n are values satisfying the relations : 0.3≤1-x-y≤0.65, 0.2≤x≤0.65, 0.001≤y≤0.2, 0.03≤z≤0.65, 4≤n≤7, 1-x-y>y and 1-x-y>x], provided that the R element is at least one rare earth element and essentially comprises La. The method comprises the steps of : mixing raw materials; calcining; pulverizing; molding; and firing, provided that a mill scale powder is used as an iron oxide raw material compounded in the step of mixing the raw materials. COPYRIGHT : (C)2009, JPO&INPIT