稀土复合氧化物纳米微晶RE_2Sn_(2-x)B'xO_7的制备、结构和红外光谱(RE=Sm,Ce;B’=Fe,Co,Ni;x=0～1.0)

Preparation, Structure and IR Spectra of Rare Earth Complex Oxides Nanocrystallines RE_2Sn_(2-x)B'xO_7(RE=Sm,Ce; B'=Fe,Co,Ni; x=0～1.0)

采用非醇盐溶胶-凝胶法首次制备了未见报道的B位掺杂烧绿石型稀土复合氧化物RE2Sn2-xB'xO7（RE＝Sm，Ce；B’＝Fe，Co，Ni；x＝0～1．0）纳米微晶.发现应用该法可降低反应温度（约200℃），缩短反应时间.制备的纳米微晶属于立方晶系，空间群为Fd3m，晶胞参数与掺杂量呈线住关系．通过红外光谱的研究，发现RE＝Ce系列试样的吸收峰频率值均低于RE＝Sm系列试样的对应吸收峰频率值：B'位不同离子的掺入，不仅导致BO6八面体的变形，出现相应的吸收峰，而且影响RE-O键的振动，使其频率有所降低．

The new nanocrystallites of the pyrochlore-type of rare earth complex oaldes with B-site doped,RE2Sn2-xB'O7(RE=Sm,Ce; B'=Fe,Co,Ni: x=0～1-0), were prepared by unalcolate sol-gel method forthe first time. The nanocrystallite sizes were from 25 to 3Onm. It is found that this method can lowerreactive temperature (about 200℃) and shorten reactive time, The crystal structure of the nanocrystallitesbelongs to.cubic system and their lattice parameters are linear1y related to the content of doped ions. RomIR spectra, it is found that:(1) the data of absorption frequency of samples with RE=Ce are lower thanthat of with RE=Sm; (2) dopants of different ions in B-site not only bring about distortion of BO6octahedron, presenting relevant absorption, but also affect the vibration of RE-O bridge, causing lowerfrequency.