中文摘要：

采用溶剂热法制备出具有尺寸可调、分散性好和强磁性的纳米γ-Fe2O3颗粒。分别采用XRD、XPS、FESEM、TEM和超导量子干涉仪（SQUID）对其结构、组分、形貌和磁性进行表征，研究氯化铁的浓度，不同的表面活性剂和反应温度对磁性纳米颗粒结构形貌和直径的影响。结果表明：制备得到的产物为反尖晶石结构、具有单分散性的γ-Fe2O3纳米颗粒，粒径在50～400 nm之间可调。反应温度对纳米颗粒的相组成和形貌影响比较显著，在140℃下得到α-Fe2O3相，在160℃下得到γ-Fe2O3相，而在180与200℃下得到Fe3O4相。纳米颗粒尺寸随着氯化铁浓度的增加而增大，随着十二烷基苯磺酸钠（SDBS）的加入而减小。在室温下，γ-Fe2O3纳米颗粒具有较强磁性，当粒径为50nm时其矫顽力可以达到1．4 kA／m。这将在磁性复合光催化剂和生物医学领域具有潜在的应用价值。

英文摘要：

Size controllable, better dispersed, hydrophilic and strong magnetic y-Fe203 nano-particles were prepared by a solvothermalmethod. XRD, XPS, FESEM, TEM and superconducting quantum interface device （SQUID） were used to characterize the y-Fe203nano-particles. Effects of ferric chloride, surfactants and reaction temperature on the product were examined. The results show that theobtained γ-Fe2O3 nano-particles have the inverse spinel structure and better dispersibility, and the sizes of y-Fe203 nano-particles can becontrolled at 50-400 nm. The effect of reaction temperature on the phases and morphology of nanoparticles is significant, α-Fe2O3 couldbe prepared at 140 ℃, γ-Fe2O3 at 160 ℃ and Fe3O4 between 180 and 200 ℃. The size of the nanoparticles increases with higher ferricchloride concentration while it decreases with the SDBS addition. The samples have strong magnetic property at room temperature. Thecoercivity is 1.4 kA/m when the particle size is 50 nm, which would be potentially applied in biology and medicine fields.