Gd_2Zr_(2-x)Ce_xO_7(0.0≤x≤2.0)的制备与表征
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摘要
为获得钆锆烧绿石基固化体固化Pu后的物理性能、物相变化及微观形貌,本研究用Ce4+模拟Pu4+,以Gd2O3、ZrO2和CeO2粉体为原料,采用高温固相法,制备不同固溶度(0～100%,按摩尔计)的系列钆锆烧绿石固化体,并对密度、硬度、物相和微观形貌等进行表征。结果表明:实验所得系列固化体的密度和硬度均随着x的增大而增大,硬度HV与x满足关系式HV=661.272 73+223.936 36x(R2=0.946 38)。在x=0.0时,所得固化体为单一的烧绿石结构;在x=0.2时,固化体从烧绿石结构转变为萤石型结构;在0.2≤x≤2.0范围内,固化体均为单一萤石型结构。固化体微观形貌不规则,呈板块状。
In order to get the physical properties,phase change and microstructure of waste forms containing plutonium,cerium with four valences was used as the simulacrum for plutonium with tetravalence.Pyrochlore Gd2Zr2O7 as waste forms was prepared by Gd2O3,ZrO2 and CeO2 powders with high temperature solid-state method.The solid solubility of pyrochlore Gd2Zr2O7 is ranged from 0 to 100%(in mole) dosage.Waste forms were characterized with density,rigidity,phase composition and micro-morphology.The results show that density and rigidity HV increase with x,rigidity and the addition of Ce satisfy the relation: HV=661.272 73+223.936 36x(R2=0.946 38).When x=0.0,the waste forms are single pyrochlore structure;when x=0.2,the waste forms transform from pyrochlore into fluorite structure.In the interval 0.2≤x≤2.0,the waste forms are single fluorite structure.Microstructure of waste forms is not regular and plate-like.
In order to get the physical properties,phase change and microstructure of waste forms containing plutonium,cerium with four valences was used as the simulacrum for plutonium with tetravalence.Pyrochlore Gd2Zr2O7 as waste forms was prepared by Gd2O3,ZrO2 and CeO2 powders with high temperature solid-state method.The solid solubility of pyrochlore Gd2Zr2O7 is ranged from 0 to 100%(in mole) dosage.Waste forms were characterized with density,rigidity,phase composition and micro-morphology.The results show that density and rigidity HV increase with x,rigidity and the addition of Ce satisfy the relation: HV=661.272 73+223.936 36x(R2=0.946 38).When x=0.0,the waste forms are single pyrochlore structure;when x=0.2,the waste forms transform from pyrochlore into fluorite structure.In the interval 0.2≤x≤2.0,the waste forms are single fluorite structure.Microstructure of waste forms is not regular and plate-like.
引文
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