CAJ | 학술논문

以金属硝酸盐和柠檬酸为主要原料,医用脱脂棉为模板,通过简单易行的模板辅助 sol-gel 法来制备高比表面积、高磁性能纳米 CoFe2 O4材料.采用 XRD,TEM,BET, VSM和Easy heat等方法研究了模板和热处理温度对所得材料组成、微观结构、磁性能和磁加热效率等的影响.结果表明：添加模板有利于获得不含杂质相的尖晶石型纳米磁性CoFe2 O4颗粒,随热处理温度的升高,颗粒的平均晶粒尺寸逐渐增加,比表面积减小.未添加模板的纳米颗粒存在较为严重的堆积现象,添加模板后所得CoFe2 O4颗粒呈近似椭球形,不同颗粒之间首尾相接,类似线形,团聚程度明显下降.添加模板后800℃热处理所得试样的平均晶粒尺寸约为70.0 nm,比表面积为23.7 m2/g,饱和磁化强度为79.0 emu/g,剩磁强度为37.1 emu/g,矫顽力为856.4 G,磁加热速率为2.95℃/s,均显著高于相同热处理温度下未加模板所制备的铁氧体颗粒.最后对类线形纳米CoFe2 O4的形成过程进行了探讨.
이금속초산염화저몽산위주요원료,의용탈지면위모판,통과간단역행적모판보조 sol-gel 법래제비고비표면적、고자성능납미 CoFe2 O4재료.채용 XRD,TEM,BET, VSM화Easy heat등방법연구료모판화열처리온도대소득재료조성、미관결구、자성능화자가열효솔등적영향.결과표명：첨가모판유리우획득불함잡질상적첨정석형납미자성CoFe2 O4과립,수열처리온도적승고,과립적평균정립척촌축점증가,비표면적감소.미첨가모판적납미과립존재교위엄중적퇴적현상,첨가모판후소득CoFe2 O4과립정근사타구형,불동과립지간수미상접,유사선형,단취정도명현하강.첨가모판후800℃열처리소득시양적평균정립척촌약위70.0 nm,비표면적위23.7 m2/g,포화자화강도위79.0 emu/g,잉자강도위37.1 emu/g,교완력위856.4 G,자가열속솔위2.95℃/s,균현저고우상동열처리온도하미가모판소제비적철양체과립.최후대류선형납미CoFe2 O4적형성과정진행료탐토.
A simple template assisted sol-gel method was used to prepare nano-size CoFe2 O4 powders with high specific surface area and magnetic properties.The influences of template and heat treated tem-peratures on the composition,microstructure,specific area,magnetic properties as well as magnetic heat-ing rate were studied through XRD,TEM,BET,VSM and RF heat tests.The results show that adding template helps to obtain pure spinel CoFe2 O4 nano-magnetic particles,and with the increase of heat treated temperature,the average grain size of the as-prepared nano-particles increases,reducing its surface area. Without template,the as-prepared nano-particles exhibit serious accumulation.After adding the template,CoFe2 O4 particles are the approximate ellipsoid,and connected one by one,similar to a line,and its ag-glomeration decreases significantly.The average grain size of nano-sized particles obtained when adding template and calcined at 800 ℃ is about 70.0 nm,its specific surface area is 23.7 m2 ·g-1 ,its Ms equals to 79.0 emu·g-1 ,its Mr equals to 37.1 emu·g-1 ,its coercive force equals to 856.4 G,and its magnetic heating rate is 2.95 ℃·s-1 .These values are all significantly higher than that of nano-sized CoFe2 O4 par-ticles obtained without template and calcined at 800 ℃.Finally,the formation process of thread-like nano-sized CoFe2 O4 particles was discussed.