【摘要】 对采用溶胶凝-胶法制备的（CoFe₂O₄）0.7/（SiO₂）_0.3纳米复合粉末进行了高压（5 GPa）处理,研究了高压下热处理温度对样品结构和磁性的影响.结果表明,在5 GPa压力下,经600℃热处理后样品中没有形成尖晶石铁氧体,当温度达到800℃时才有CoFe₂O₄形成.随着热处理温度的升高,CoFe₂O₄纳米颗粒的平均晶粒尺寸从69 nm增大到287 nm,样品的饱和磁化强度从39.6 A·m²/kg增大到51.2 A·m²/kg,而矫顽力从44.6 k A/m减小到11.0 k A/m.样品磁性是变化与CoFe₂O₄纳米颗粒的增大有关系.更多还原

【Abstract】 The effects of annealing temperature on the structure and magnetic properties for（ CoFe₂O₄） 0. 7/（ SiO₂）_{0. 3} nanocomposites prepared by sol-gel model under high pressure have been investigated. The research shows that there is without spinel ferrite when annealing temperature is 600 ℃ under the pressure being 5GPa. When the temperature reaches 800 ℃,CoFe₂O₄ nanoparticles appear. With the increase of annealing temperature,the average grain size of CoFe₂O₄ nanoparticles increases from 69 to 287 nm,the saturation magnetization of the samples increases from 39. 6 to 51. 2 A · m²/kg,the coercive decreased from 44. 6 to11. 0 k A/m. The changes of magnetic for the samples have relations with the increasing of nanoparticles.更多还原