Influence of the metal nitrates to citric acid molar ratio on the combustion process and phase constitution of barium hexaferrite particles prepared by sol-gel combustion method

被引:130
作者
Mali, A [1 ]
Ataie, A [1 ]
机构
[1] Univ Tehran, Fac Engn, Dept Met & Mat, Tehran, Iran
关键词
sol-gel processes; calcination; magnetic properties; ferrites; hard magnets;
D O I
10.1016/j.ceramint.2003.12.178
中图分类号
TQ174 [陶瓷工业]; TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
A novel sol-gel combustion process was used to synthesize the ultrafine particles of barium hexaferrite. The nitrate-citrate gels were prepared from metal nitrates and citric acid solutions under various molar ratios of the metal nitrates to citric acid of 0.5, 1, 1.5 and 3 by sol-gel process. The results showed that the nitrate citrate gels exhibit a self-propagating behavior after ignition in air at room temperature. The thermal decomposition of nitrate-citrate gels and the phase evolution of calcined powder were investigated respectively by DTA/TG and XRD techniques. Scanning electron microscope was used to characterize the microstructure of the products. The results revealed that the formation temperature and the crystallite size of barium hexaferrite are influenced significantly by the molar ratio of the metal nitrates to citric acid. The formation temperature of barium hexaferrite decreases with increasing the molar ratio of the metal nitrates to citric acid. (C) 2004 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
引用
收藏
页码:1979 / 1983
页数:5
相关论文
共 12 条
[1]   Barium hexaferrite monodispersed nanoparticles prepared by the ceramic method [J].
Benito, G ;
Morales, MP ;
Requena, J ;
Raposo, V ;
Vázquez, M ;
Moya, JS .
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 2001, 234 (01) :65-72
[2]   BARIUM FERRITE PARTICULATES PREPARED BY A SALT-MELT METHOD [J].
CHIN, TS ;
HSU, SL ;
DENG, MC .
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 1993, 120 (1-3) :64-68
[3]  
Cullity BD, 1978, ELEMENTS XRAY DIFFRA
[4]  
Kojima H., 1982, FERROMAGNETIC MAT, V3
[5]   An ultrafine barium ferrite powder of high coercivity from water-in-oil microemulsion [J].
Liu, XY ;
Wang, J ;
Gan, LN ;
Ng, SC ;
Ding, J .
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 1998, 184 (03) :344-354
[6]   Improving the magnetic properties of hydrothermally synthesized barium ferrite [J].
Liu, XY ;
Wang, J ;
Gan, LM ;
Ng, SC .
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 1999, 195 (02) :452-459
[7]   Fine barium hexaferrite powder prepared by the crystallisation of glass [J].
Rezlescu, L ;
Rezlescu, E ;
Popa, PD ;
Rezlescu, N .
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 1999, 193 (1-3) :288-290
[8]   PREPARATION AND MAGNETIC-PROPERTIES OF BARIUM FERRITE FINE PARTICLES BY THE COPRECIPITATION SALT CATALYSIS METHOD [J].
SAKAI, H ;
HANAWA, K ;
AOYAGI, K .
IEEE TRANSACTIONS ON MAGNETICS, 1992, 28 (06) :3355-3362
[9]   Mechanism of the formation of nanoscale M-type barium hexaferrite in the citrate precursor method [J].
Sankaranarayanan, VK ;
Khan, DC .
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 1996, 153 (03) :337-346
[10]  
Stablin H, 1982, FERROMAGNETIC MATERI, V3