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Growth of monodisperse nanospheres of MnFe_2O_4 with enhanced magnetic and optical properties
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M.Yasir Rafique 潘礼庆 Qurat-ul-ain Javed M.Zubair Iqbal 邱红梅 M.Hassan Farooq 郭振刚 M.Tanveer 《中国物理 B》2013,(10):453-459
Highly dispersive nanospheres of MnFe204 are prepared by template free hydrothermal method. The nanospheres have 47.3-nm average diameter, narrow size distribution, and good crystallinity with average crystallite size about 22 nm. The reaction temperature strongly affects the morphology, and high temperature is found to be responsible for growth of uniform nanospheres. Raman spectroscopy reveals high purity of prepared nanospheres. High saturation magnetization (78.3 emu/g), low coercivity (45 Oe, 10e = 79.5775 A.cm-1), low remanence (5.32 emu/g), and high anisotropy constant 2.84 × 10^4 J/m3 (10 times larger than bulk) are observed at room temperatures. The nearly snperparamagnetic behavior is ~ spin due to comparable size of nanospheres with superparamagnetic critical thameter Dcr spm The high value of Keff may be due to coupling between the pinned moment in the amorphous shell and the magnetic moment in the core of the nanospheres. The nanospheres show prominent optical absorption in the visible region, and the indirect band gap is estimated to be 0.98 eV from the transmission spectrum. The prepared Mn ferrite has potential applications in biomedicine and photocatalysis. 相似文献
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为促进新形势下的“大学物理实验”课程体系改革,推动“高素质、创新型”人才培养朝新方向、高水平前进,北京科技大学“大学物理实验课反溯教学方法研究”课题组提出了物理实验课反溯教学方法,将现代科技的最新发展引入课程,对反溯教学方法进行了探索。课题组从实验现象出发,引导学生反溯基本物理学概念、原理和现象,并相应组织编排物理实验内容,激发学生的探索欲和创造欲,全面提升学生的学习兴趣和学习能力。课题组从实验室建设、新教材建设、新实验编排、本科生科技创新、实验课程与最新科研项目结合等多个角度出发,对“大学物理实验”课程体系进行了全面深化,促进学生变“要我学”为“我要学”,并取得了一系列教学成果。 相似文献
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建立高效液相色谱法测定复方托吡卡胺滴眼液中有关物质的含量测定方法.色谱柱为Agilent Eclipse XDB-C8(150cm×4.6mE,5μm),流动相为甲醇-0.01mol/L辛烷磺酸钠溶液(用磷酸调节pH值至3.0)(46∶54),测定波长为265nm,流速为1.0mL/min,柱温为30℃,进样体积20μL.托吡卡胺和盐酸去氧肾上腺素与有关物质能完全分离,总杂质含量限度小于0.5%.该方法准确、简便、快速、可靠,能有效控制复方托吡卡胺滴眼液中有关物质的含量. 相似文献
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