摘要
用X射线衍射、透射电镜和穆斯堡尔谱对由掺杂了不同比例Sb的溶胶—凝胶系统制备得的α-Fe_2O_3纳米晶的晶粒度和精细结构进行了研究。结果显示,未掺杂时由Fe(OH)_3非品相干凝胶晶化而得的α-Fe_2O_3相晶粒较大;掺Sb后,干凝胶晶化时一部分Sb参与形成FeSbO_4 晶相,另外的Sb原子进入α-Fe_2O_3晶相中,形成间隙式固溶体。系统中掺杂量增多,固溶于α-Fe_2O_3晶相中的Sb浓度相应也增大,它们很可能在晶粒的表面相对富集,形成扩散势垒,起抑制晶粒长大的作用。在高温下热处理时,固溶体中的杂质原子脱溶析出,晶粒快速长大。
The grain size and fine structure of Sb doped α-Fe2O3 nanocrystalline phase obtained by sol-gel process have been studied with X-ray diffraction, Transmission electron microscopy and Mossbauer spectrometer. The results show that, before doping, the grain size of α-F2Q3 formed through crystallization of Fe(OH)3 amorphous dry gel is rather coarse, after Sb doping, some of the Sb atoms participate in the formation of FeSbO4, while others enter the α-Fe2O3 lattice and form the interstitial solid solution. They seem to be mainly segregated near the surface of the grains and form the barrier for atomic diffusion, thus take the role of restraining the grain growth during heating. When heat treated at high temperature, the Sb solute atoms separate out from α-Fe2O3 phase and enable the rapid growth of the grains.
出处
《物理测试》
CAS
1999年第1期14-17,共4页
Physics Examination and Testing
基金
福建省自然科学基金(E96005)
