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采用溶胶-凝胶自燃烧法制得了柠檬酸盐络合物,该络合物经960℃煅烧7小时得到了纳米尺寸的Y2BaCuO5(Y211)细粉。利用XRD对不同pH下的纳米尺寸Y211粉体特性如物相鉴定,晶粒尺寸,晶格常数等进行测量。实验发现干凝胶在空气中点燃后存在自蔓延燃烧。初始溶液中pH值影响了干凝胶自燃烧的过程,决定了自燃烧和煅烧粉体的晶格常数,密度,体积以及粒子尺寸。当pH=7,煅烧粉体的XRD图谱表明煅烧后粉体的平均晶粒尺寸(25nm)远小于自燃烧粉体的平均晶粒尺寸(48nm)。此外,pH=5的煅烧粉体的晶格常数有一个最小值,而密度则达到了最大值6.224g/cm3。
The citrate complex was prepared by the sol-gel auto-combustion method. The complex was calcined at 960 ℃ for 7 hours to obtain the nano-size Y2BaCuO5 (Y211) fine powder. XRD was used to measure the properties of nanometer size Y211 powders at different pHs such as phase identification, grain size, lattice constant and so on. Experiments found that there is self-sustaining combustion of xerogels after ignition in the air. The pH of the initial solution affected the self-combustion process of the xerogel and determined the lattice constant, density, volume, and particle size of the self-burning and calcined powder. When pH = 7, the XRD pattern of the calcined powder indicates that the average grain size (25 nm) of the calcined powder is much smaller than the average grain size (48 nm) of the self-combusting powder. In addition, the lattice constant of calcined powder with pH = 5 has a minimum value, while the density reaches the maximum of 6.224g / cm3.