LaMnO_3纳米线的硬模板法合成及磁性能研究

Synthesis of nanowires LaMnO_3 by hard template method and research on their magnetic properties research

以介孔材料二氧化硅SBA-15为硬模板合成了具有规则纳米线排列的LaMnO_3,研究了煅烧温度、模板孔道结构对产物比表面积的影响及比表面积大小对纳米LaMnO_3材料磁性的影响.在650~700℃煅烧温度范围内,煅烧温度升高,比表面积增加,煅烧温度过高将会破坏模板的稳定性进而影响产物的结构,致使产物比表面积下降.同一煅烧温度700℃下,模板孔径越大,产物比表面积越大.纳米材料LaMnO_3的磁性受到表面及界面不饱和自旋磁矩的影响,产生铁磁性,比表面积越大,不饱和自旋磁矩越多,铁磁性越强.

Nanowires LaMnO_3 with ordered arrangement were synthesized by the hard template method with the template of the mesoporous silica dioxide SBA-15.The effect of the calcined temperature and the structure of the template on the specific surface of the samples were researched.In the temperature region of 650-700℃,the specific surface increased with the calcined temperature,but the extra-high temperature would destroy the stability of the template,destroyed the structure of the samples,and decreased the surface of the material.Under the same calcined temperature,the specific surface increased with the pore diameter of the template.The magnetic of nano LaMnO_3 could be influenced by the uncompensated surface and the interface spins moments.The larger of the specific surface,the more of the surface uncompensated spin moments,and the stronger of ferromagnetic.