镍铁氧体/粉煤灰空心微珠复合粉体的制备及电磁性能  

Preparation and Electromagnetic Property of Nickel Ferrite /Fly-ash Cenospheres Composited Powder

作　　者：李桂金[1,2] 白志民[2] 马忠诚[1] 文寨军[1] 

机构地区：[1]中国建筑材料科学研究总院,北京100024 [2]中国地质大学(北京)材料科学与工程学院,北京100083

出　　处：《硅酸盐学报》2015年第2期231-236,共6页Journal of The Chinese Ceramic Society

基　　金：国家科技支撑计划课题(2013BAE09B01);大洋协会"十一五"基金项目(DYXM-115-01-4-08)

摘　　要：利用柠檬酸–硝酸盐溶胶–凝胶自蔓延燃烧法,在室温下制备了以粉煤灰空心微珠为基核、以镍铁氧体为包覆壳体的复合粉体,分析了复合粉体的物相、形貌、表面成分与电磁参数,探讨了复合粉体的形成机理。研究表明,自蔓延燃烧过程中,镍铁氧体通过非均匀成核方式在空心微珠表面成核、生长、延展,最终形成完整包覆层。自燃烧复合粉体包覆层含有少量Fe Ni3相,经900℃热处理后消失。由于包覆层物相、结构及基核间的微小区别,使得在2~18 GHz,自燃烧复合粉体的介电常数、磁导率与热处理复合粉体存在一定差异。A composited powder of fly-ash cenospheres coated by nickel ferrite was prepared by a citrate nitrate sol-gel auto-combustion method at room temperature. The phase, micrograph, surface element and electromagnetic property were analyzed. The coating mechanism was also discussed. The results indicate that nickel ferrite nucleats, grows and spreads in the fly-ash cenospheres in a heterogeneous nucleation way during auto-combustion process, and forms the complete coating layer on the surface of cenospheres. The coating layer of auto-combustion composited powder has a little FeNi3 phase that is eliminated after heat treatment at 900℃. Small difference between the phase and structure of coating layer and base kernel could result in different permittivities and permeabilities of auto-combustion powder and heat treatment composited powder at 2?18 GHz.

关 键 词：镍铁氧体/粉煤灰空心微珠 自蔓延燃烧法 包覆机理 电磁性能 

分 类 号：TB383.3[一般工业技术—材料科学与工程]