层状钙钛矿型氧化物BaYb_xMn_(1-x)O_3的制备与结构分析

以BaCO_3,MnCO_3和Yb_2O_3为原料,采用传统固相烧结法,在1300 ℃下合成了两种新的化合物12R-Ba_4YbMn_3O_(11.5)和10H-Ba_5YbMn_4O_(14.5).用X射线能谱(EDS)微区成分分析和氧化还原滴定法确定两种化合物的化学式,用选区电子衍射(SAED)以及粉末X射线衍射Rietveld结构精修等手段分析测定了对化合物的晶体结构.12R-Ba_4YbMn_3O_(11.5)的空间群为R-3m,晶胞参数为a=0.578 nm,c=2.850 nm;10H-Ba5 YbMn_4O_(14.5)的空间群为P63/mmc,晶胞参数为a=0.575 nm,C=2.377 nm.

Preparation and Structure Analysis of Layered Perovskite BaYb_xMn_(1-x)O_3 Oxides

With BaCO_3, MnCO_3 and Yb_2O_3 fits raw ma-terials, the two new compounds, 12R-Ba_4YbMn_3O_(11.5) and 10H-Ba_5YbMn_4O_(14.5), were synthesized using tra-ditional solid-state reaction at 1300℃. The chemical formulas of the composites were determined through EDS analysis and redox titration, the crystalline struc-ture of the compounds were determined through select-ed area electron diffraction and Rietveld refinement based on powder X-ray diffraction. It was shown that the 12R-Ba_4YbMn_3O_(11.5) belonged to the R-3m space group with the lattice parameter of a = O. 578 nm and c =2.850 nm; and the 10H-Ba_5YbMn_4O_(14.5) belonged to the P63/mmc space group with the lattice parameter of a = 0. 575 nm and c = 2.377 nm.