稀土镧添加氧化锆的合成与物相分析研究

以硝酸锆、硝酸镧和柠檬酸为原料，原位合成了稀土镧（La）掺杂氧化锆（ZrO₂）和锆酸镧/氧化锆（La₂Zr₂O₇/ZrO₂）复合材料。采用X射线衍射（XRD）和拉曼光谱（Raman）作为分析和表征手段，研究了稀土La掺杂ZrO₂和La₂Zr₂O₇/ZrO₂复合材料的物相组成以及La₂Zr₂O₇/ZrO₂复合材料的高温热稳定性。研究结果表明：稀土La很难进入ZrO₂晶格形成固溶体，当稀土La掺杂量较少时，生成以m-ZrO₂为主相的m-ZrO₂和La₂Zr₂O₇的复合材料；当稀土La掺杂量较大时，生成以La₂Zr₂O₇为主相的t-ZrO₂和La₂Zr₂O₇的复合材料。在1 400 ℃煅烧6 h条件下，LZZ11（按La₂Zr₂O₇与ZrO₂物质的量比为1∶[KG-*2]1称取原料制备的样品）中的t-ZrO₂转变为m-ZrO₂相，此时La₂Zr₂O₇失去了对ZrO₂的稳定作用。

Study on synthesis and phase composition of rare earth La doping ZrO2

Rare earth La doping ZrO₂ and composite La₂Zr₂O₇/ZrO₂ were synthesized by in situ synthesis method with Zr(NO₃)⁴•3H₂O,La(NO₃)³•6H₂O,and C₆H₈O₇•H₂O as raw materials.Phase composition and high temperature stability of the products were studied by analysis means of XRD and Raman.Results indicated that it was difficult for La to enter crystal lattice of ZrO₂ being solid solution,when the doping amounts of La were less,rare earth doping ZrO₂ was composed of m-ZrO₂ and La₂Zr₂O₇;when the doping amounts of La were more,rare earth doping ZrO₂ was composed of t-ZrO₂ and La₂Zr₂O₇.The t-ZrO₂ was converted into m-ZrO₂ in LZZ11 (the sample prepared on the proportion of 1∶1 of La₂Zr₂O₇ and ZrO₂ in amount-of-substance ratio) by calcining at 1 400 ℃ for 6 h,and it was clear that La₂Zr₂O₇ was no conducive to the stabilizing of ZrO₂. 