【摘要】 固体滴定法是研究固溶量的一种新方法 .本实验选择Mn -Al2 O3色料 ,给其中加入Cr2 O3,通过测定反射光谱f(R)、晶格常数、电子自旋共振 (ESR) ,并计算晶格常数 ,分别得到加入Cr2 O3前后的Mn -Al2 O3的反射光谱与晶格常数的变化 ,依据该数据来推定着色离子Mn的固溶量及化学状态 .为确定Mn -Al2 O3红色料中Mn的固溶量 ,给其中加入Cr2 O3,它使Mn -Al2 O3红的色调发生变化 .在此过程中发生如下反应 :Cr3+ +Mn3+ Cr4+ +Mn2 + .Mn -Al2 O3红色料在反射光谱 5 2 0nm处有吸收峰值 ,给其中添加Cr2 O3后峰值减小 ,用Cr3+ 的固溶量 (即Cr2 O3的添加量 )和峰值Δf(R)作图并延伸图线至Δf(R) =0点 ,此点对应的Cr2 O3值即为Mn3+ 的固溶量 (Mn2 O3的浓度 ) .实验证明 ,利用固体滴定法在一定精度范围内测定发色元素的固溶量取得一定程度成功 .锰红色料中的发色离子状态为Mn3+ .添加Cr2 O3后 ,Cr能置换Mn -Al2 O3中的Mn .铬是以Cr3+ 化学状态固溶到Al2 O3中的更多还原

【Abstract】 In this study, the changes in reflection spectrum and lattice constant of Mn-Al 2O 3 pink pigment as a result of addition of Cr 2O 3 were observed by measuring the reflection spectrum f (R), lattice constant, electron spin resonance (ESR) and calculating the lattice constant, based on which the solid solubility and the chemical state of coloring ion Mn were deduced. Following reaction mechanism is considered when Cr 2O 3 is added:Cr 3+ +Mn 3+ →Cr 4+ +Mn 2+ . The absorption apex value f (R) is at 520 nm on the reflection spectrum and a figure can be made using both Δ f(R) and the solid solubility of Cr 3+ ( i.e. the adding amount of Cr 2O 3). Extending the curve letting Δ f(R) =0, we get a point, which is the solid solubility of Mn 3+ . The conclusion is reached that the solid solubility of coloring elements can be measured by solid titration to a satisfied accuracy. When Cr 2O 3 added, Mn in Mn-Al 2O 3 pink pigment is in the state of Mn 3+ and replaces by Cr 3+ .更多还原