磁性材料SMC PPT.ppt

1、Meeting 5(24/5/2011)Soft Magnetic Composites,Shen Hongxian and Hao Peng,SEM for Ferrite NiZnFe2O4,Magnetic Properties of Ferrites,Field (Gs),Moment/Mass emu/g,Field (Gs),Moment/Mass emu/g,No Heating 未加热,Hard Ferrites,Field (Gs),Moment/Mass emu/g,Heat at 500 加热到500 保温2h,Field (Gs),Moment/Mass emu/g,H

2、eating at 700 加热700摄氏度保温2h,B,H,m=B/H,Soft，500,0,500,700t,TGA of BaFe12O9,Resistivity of BaFe12O9,Layered Double Hydroxides,Synthesis Steps for Layered Double Hydroxides (LDH) Formation,双层氢氧化物,The most common method to prepare LDHs is by co-precipitation of metallic salts with a concentrated alkaline

3、 solution. （通用制备方法：金属盐在浓缩碱溶液中的共沉淀） Requires prolonged hydrothermal treatments that increase the cost. Enormous amounts of water are required to wash the final products. 缺点：热处理时间长，耗费水比较多,Continuous production of LDHs by an in-line dispersion-precipitation method It employs an alkaline solution to pre

4、cipitate the metallic salts, the purification and handling problems are not avoided.（用碱溶液就无法避免洗涤和提纯的步骤。） Another approach was the preparation of LDHs using metal oxides/hydroxides（金属氧化物/金属氢氧化物） It required long aging times and the final products contained, among other phases, also need to adjust the

5、 pH （需要的时间较长，适当的调整pH，可以直接过滤 干燥）,LDHs 1% Fe粉,5% LDHs,HPs samples,HPs samples,SHXs samples,SHXs samples,热液合成法制备LDHs， 3%， 湿法混合,NiZnFe2O4, 1%, pH=5 湿法混合,NiZnFe2O4, 1%, pH=5 湿法混合，Fe粉HNO3处理,北京友信昌豪铁粉环形试件,Torroid results:,Use hard magnetic coating to form torroids.,Purchase lubricant (B-N) to improve density,Do e-m measurements.,Torroid results:,Use hard magnetic coating to form