Peng Yuandong, Xia Chao, Cui Minghui, Yao Zhixin, Yi Xuwu
State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, PR China.
State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, PR China.
Ultrason Sonochem. 2021 Mar;71:105369. doi: 10.1016/j.ultsonch.2020.105369. Epub 2020 Oct 19.
Nano-spinel ferrites synthesized via chemical co-precipitation method are small in size and have serious agglomeration phenomenon, which makes separation difficult in the subsequent process. NiCuZnFeO ferrites nanoparticles were synthesized via co-precipitation assisted with ultrasonic irradiation produced by ultrasonic cleaner with 20 kHz frequency using chlorinated salts and KOH as initial materials. The effects of ultrasonic power (0, 40 W, 60 W, 80 W) and reaction temperature on the microstructure and magnetic properties of ferrite nanoparticles were investigated. The structure analyses via XRD revealed the successful formation of pure (NiCuZn)FeO ferrites nanospinel without any impurity. The crystallites sizes were less than 40 nm and the lattice constant was near 8.39 Å. The TEM showed ferrite particle polygonal. M-H analyses performed the saturation magnetization and coercivity of ferrite nanoparticles obtained at the reaction temperature of 25℃ were higher than at 50℃ with same power. The samples exhibited the highest values of Ms 55.67 emu/g at 25℃ and 47.77 emu/g at 50℃ for 60 W and the lowest values of Hc 71.23 Oe at 25℃ for 40 W and 52.85 Oe at 50℃ for 60 W. The squareness ratio (SQR) were found to be lower than 0.5, which revealed the single magnetic domain nature (NiCuZn)FeO nanoparticles. All the outcomes show the ultrasonic irradiation has positive effects on improving the microstructure and increasing magnetic properties.
通过化学共沉淀法合成的纳米尖晶石铁氧体尺寸小且存在严重的团聚现象,这使得在后续过程中分离困难。以氯化物盐和氢氧化钾为原料,利用频率为20kHz的超声波清洗器产生的超声辐照辅助共沉淀法合成了NiCuZnFeO铁氧体纳米颗粒。研究了超声功率(0、40W、60W、80W)和反应温度对铁氧体纳米颗粒微观结构和磁性能的影响。通过X射线衍射(XRD)进行的结构分析表明成功形成了纯的(NiCuZn)FeO铁氧体纳米尖晶石,无任何杂质。晶粒尺寸小于40nm,晶格常数接近8.39埃。透射电子显微镜(TEM)显示铁氧体颗粒为多边形。磁滞回线(M-H)分析表明,在相同功率下,反应温度为25℃时获得的铁氧体纳米颗粒的饱和磁化强度和矫顽力高于50℃时的。对于60W,样品在25℃时表现出最高的Ms值55.67emu/g,在50℃时为47.77emu/g;对于40W,在25℃时Hc的最低值为71.23奥斯特(Oe),对于60W,在50℃时为52.85奥斯特(Oe)。方形度比(SQR)低于0.5,这表明(NiCuZn)FeO纳米颗粒具有单磁畴性质。所有结果表明超声辐照对改善微观结构和提高磁性能具有积极作用。