Zn^(2+)对MnZn铁氧体结构、磁性能和磁热效应的影响

Effect of Zn^(2+) on structure,magnetic properties and thermomagnetic effect of MnZn ferrites

采用溶胶-凝胶自燃烧法制备了不同Zn2+含量的纳米MnZn铁氧体微粒,并通过XRD、VSM、TEM等方法研究了Zn2+含量对MnZn铁氧体结构、磁性能及在外磁场作用下磁热效应的影响。结果表明,Zn2+含量对MnZn铁氧体的结构与性能有重要的影响,其中成分为Mn0.8Zn0.2Fe2O4的铁氧体微粒,具有最高的饱和磁化强度和磁热效应,10mg的该样品在频率为60kHz的外磁场诱导下,20min内使得1ml去离子水升温了32℃,显示出优良的磁热性能。同时,通过调节Zn2+含量实现了MnZn铁氧体发热量的可调性。随着Zn2+含量的增加,Mn1-xZnxFe2O4的矫顽力Hc和剩余磁化强度Br不断减小,而饱和磁化强度Ms先增大后减小,在x=0.2处达到最大值,约为44.6(A.m2)/kg。

MnZn ferrite nanoparticles were prepared by using sol-gel auto-combustion method.The effect of Zn^2＋ on structure,magnetic properties and thermomagnetic effect were investigated with transmission electron microscope（TEM）,X-ray diffractometer（XRD） and vibration sample magnetism analysis system（VSM）,etc.The results show that Zn^2＋ has great influence on structure and property of MnZn ferrite.Among the samples prepared,Mn0.8Zn0.2Fe2O4 possessed the maximal saturation magnetization Ms and thermomagnetic effect.10mg these samples led the 1mL deionized water increase 32℃ in 20min under a 60kHz alternating magnetic field,showing the sufficient heating ability.Furthermore,the thermomagnetic effect of MnZn ferrite was adjustable by adjusting Zn^2＋content.When the Zn^2＋content increases,the coercive force Hc and remnant magnetization Br reduse,but the saturation magnetization Ms increases first and reduses subsequently,the maximal Ms to be obtained while the Zn^2＋content is 0.2,the utmost valu is up to 44.6（A·m^2）/kg.