Mn-Zn fetrite powders were prepared by hydrothermally aging the coprecipitates of compositional metal ions using ammonium hydroxide as a precipitant. R value (alkalinity) = (moles of added OH-)/[(moles of added Zn~2+) X 2 + (moles of added Mn~2+) X 2 + (moles of added Fe~3+) X 3] was introduced to adjust the amount of added ammonia. The results show that the R value of starting suspension and hydrothermal time have similar and dominant effects on the composition, spinel ratio, and crystallite size of synthesized powders. From the analyses of x-ray diffraction (XRD) and inductively-coupled plasma (ICP), it notes that no α-Fe_2O_3 peak in the XRD pattems of powders synthesized at R = 2-3, l50 deg. C X 2 h, may be due to lower degree of crystallinity and less amount of α-Fe_2O_3 existing in these powders. Both the increase of hydrothermal time and of R value can promote the crystallinity of powders and also cause a significant loss of zinc, hinting that in the hydrothermal process, the loss of zinc may play a crucial role in the crystallinity of hydrothermally synthesized powders.
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机译：通过使用氢氧化铵作为沉淀剂对组成金属离子的共沉淀物进行水热老化来制备Mn-Zn铁氧体粉末。 R值（碱度）=（添加的OH-的摩尔数）/ [（添加的Zn〜2 +的摩尔数）X 2 +（添加的Mn〜2 +的摩尔数）X 2 +（添加的Fe〜3 +的摩尔数）X 3引入]以调节氨的添加量。结果表明，起始悬浮液的R值和水热时间对合成粉末的组成，尖晶石比和微晶尺寸具有相似和显着的影响。通过对X射线衍射（XRD）和电感耦合等离子体（ICP）的分析，发现在R = 2-3、150度下合成的粉末的XRD图谱中没有α-Fe_2O_3峰。 C X 2 h可能归因于这些粉末中较低的结晶度和较少的α-Fe_2O_3含量。水热时间的增加和R值的增加都可以促进粉末的结晶度，并且还导致锌的大量流失，这表明在水热过程中，锌的损失可能在水热合成粉末的结晶度中起关键作用。
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