中文摘要：

结合水热法和超声法的优点,首先用水热法合成出晶粒尺寸约为15nm的Fe3O4纳米实心球,用硝酸处理并最终在硝酸铁溶液中超声Fe3O4纳米实心球,得到了晶粒尺寸约在5nm的γ-Fe2O3纳米空心球.X射线衍射（XRD）、X射线散射能谱（EDS）、扫描/透射电子显微镜（SEM/HRTEM）、氮气和孔径分布（BJH）证明所得的样品为高纯的具有孔结构的γ-Fe2O3纳米空心球.超导量子干涉仪（SQUID）和稳定性实验显示,γ-Fe2O3纳米空心球在室温下为超顺磁性,且具有较高的饱和磁矩和化学稳定性,这为γ-Fe2O3纳米空心球在药物运输领域的应用提供了依据.

英文摘要：

Combine the advantages of hydrothermal approach and ultrasonic method,Fe3O4 solid nanospheres with grain sizes of ～15 nm are prepared by hydrothermal approach.Then treat these Fe3O4 solid nanospheres with acid and finally sonicate in ferric nitrate solution,γ-Fe2O3 hollow nanospheres with grain size of -5 nm are obtained.X-ray diffraction（XRD） and energy dispersive spectrometer（EDS）,scanning electron/transmission electron microscopy（SEM/TEM）,nitrogen adsorption and pore size distribution（BJH） prove that the sample is high purity γ-Fe2O3 hollow nanospheres with pore structure.Superconducting quantum interference device and stability experiment demonstrate that γ-Fe2O3 hollow nanospheres are superparamagnetism with a high saturation magnetization and chemical stability at room temperature.