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公开(公告)号：US5078984A
公开(公告)日：1992-01-07
申请号：US358614
申请日：1989-05-30
CPC分类号： B82Y30/00 , C01G49/0036 , G11B5/70678 , C01P2004/22 , C01P2004/52 , C01P2004/64 , C01P2006/12
摘要： A process for producing microcrystalline barium ferrite platelets which comprises: forming an aqueous alkaline dispersion containing coprecipitates of hydroxides of barium ions, iron (III) ions, and optionally ions of a substituent element; heating the dispersion to a temperature of not less than 50.degree. C. and not more than the boiling point of the dispersion under an atmospheric pressure to convert the coprecipitates to precursors of the barium ferrite; calcining the precursors to provide microcrystalline barium ferrite platelets; the improvement comprising the step of adding a carbonating agent such as sodium carbonate to the aqueous alkaline dispersion before or after the heating of the aqueous dispersion to insolubilize water soluble barium ions therein, and the step of calcining the barium ferrite precursors in the presnece of sodium sulfate at temperatures of 700.degree.-900.degree. C., to provide microcrystalline barium ferrite platelets of about 0.03-0.1 .mu.m in average particle size and 2-5 in planarity ratio.
摘要翻译： 一种生产微晶钡铁氧体薄片的方法，包括：形成含有钡离子的氢氧化物，铁（III）离子和任选的取代基元素的离子的共沉淀物的水性碱性分散体; 将分散体在大气压下将分散体加热至不低于分散体的50℃以上的温度，将共沉淀物转化为钡铁氧体的前体; 煅烧前体以提供微晶钡铁素体血小板; 所述改进包括在水性分散体加热之前或之后向碳酸钠水溶液中加入碳酸酯如碳酸钠的步骤，以使其中的水溶性钡离子不溶化;以及在钠前体中煅烧钡铁氧体前体的步骤 硫酸盐，在700-900℃的温度下，得到平均粒度为约0.03-0.1μm，平均粒径为2-5μm的微晶钡铁氧体血小板。
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2.发明授权Process for producing microcrystalline Co/Ti-substituted barium ferrite platelets 失效微晶Co / Ti取代钡铁氧体血小板的制备方法
公开(公告)号：US4960582A
公开(公告)日：1990-10-02
申请号：US387965
申请日：1989-08-01
CPC分类号： H01F1/11 , G11B5/70678
摘要： A process of producing a spinel structure Ni/Zn ferrite-modified, Co/Ti-substituted microcrystalline barium ferrite platelets having an average particle size of 0.03-0.15 .mu.m, a temperature coefficient of coercive force of not more than +1 Oe/.degree. C., including small absolute values in negative region, and a saturated magnetization of not less than 56 emu/g, which comprises: forming substantially amorphous preecursors of Co/Ti-substituted barium ferrites; adding an aqueous solution of nickel salts to the dispersion of the precursors of Co/Ti-substituted barium ferrites, and subjecting the slurry to hydrothermal reaction, thereby to provide precursors of spinel structure nickel ferrite-modified, Co/Ti-substituted barium ferrites; depositing a water insoluble zinc compound on the precursors; and calcining the precursors in the presence of barium chloride, washing the calcined products to remove therefrom the barium chloride, and drying.
摘要翻译： 制造平均粒径为0.03〜0.15μm的尖晶石结构体的Ni / Zn铁氧体改性的Co / Ti取代的微晶钡铁氧体血小板，矫顽力的温度系数不大于±1e /℃ 包括负区域的小绝对值和不小于56emu / g的饱和磁化强度，其包括：形成Co / Ti取代的钡铁氧体的基本上无定形的预测器; 在钴/钛取代的钡铁氧体前体的分散体中加入镍盐水溶液，并对浆料进行水热反应，从而提供尖晶石结构镍铁氧体改性的Co / Ti取代的钡铁氧体的前体; 在前体上沉积不溶于水的锌化合物; 并在氯化钡存在下煅烧前体，洗涤煅烧产物以从其中除去氯化钡并干燥。
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