摘要
磁性 Fe3O4 纳米粒子在纳米医学领域展现出巨大的应用前景.饱和磁化强度和磁各向异性对于 Fe3O4纳米粒子在药物输送和磁热疗中的应用至关重要.在此,通过密度泛函理论计算,仔细研究了 3d和 4d过渡金属元素的掺杂对 Fe3O4 磁矩及磁各向异性的影响.结果表明,Fe3O4 中Zn和Cd的掺杂会增大总磁矩,而其他 3d和 4d过渡金属元素的掺杂会降低总磁矩.有趣的是,Cd 的掺杂也会大大增大磁各向异性.本文结果表明,掺杂 Cd是提高 Fe3O4 作为药物输送和磁热疗材料性能的可行方法.
Abstract
Magnetic Fe3O4 nanoparticles show promising applications in nanomedicine.The saturation magnetization(MS)and magnetic anisotropy are critical for the applications of Fe3O4 nanoparticles in drug delivery and magnetic hyperthermia.Here,by density functional computation,the doping effects of 3d and 4d transition metal elements(including Sc,Ti,V,Cr,Mn,Fe,Co,Ni,Cu,Zn,Y,Zr,Nb,Mo,Tc,Ru,Rh,Pd,Ag and Cd)on the magnetic properties of Fe3O4 are investigated in-depth.A conventional cell of Fe3O4,containing 24 Fe atoms and 32 O atoms,has been used to investigate the doping of group III elements.One 3d or 4d atom is doped in one conventional cell of Fe3O4,resulting in the formation of X0.125Fe2.875O4 where X represents the dopant.The results show that the doping of most 3d and 4d transition metal elements will reduce the total magnetic moment,while the doping of Ag,Zn and Cd in Fe3O4 will increase the total magnetic moment by 19%-22%.However,it is hard to dope Ag into Fe3O4 according to the positive formation energy.Therefore,Zn and Cd are good candidates to improve the MS of Fe3O4.The doping of Zn and Cd has also an influence on the magnetic anisotropy of Fe3O4.For Zn0.125Fe2.875O4,the magnetic anisotropy energy is about 0.25 meV per cell,which is slightly larger than that of intrinsic Fe3O4(0.2 meV per cell).Interestingly,the doping of Cd(Cd0.125Fe2.875O4)will greatly increase the magnetic anisotropy energy to 0.8 meV per cell,which is significant for the specific absorption rate in the magnetic hyperthermia application.In addition,the doping of Zn and Cd will not induce any defect states in the band gap according to the density of states.Zn0.125Fe2.875O4 and Cd0.125Fe2.875O4 are both semiconducting and both the top of valence band and the bottom of conduction band originate from octahedral Fe.This is because the impurity states are very deep in energy.Our research results show that doping Cd is a feasible way to improve the performance of Fe3O4 as a material for drug delivery and magnetic hyperthermia.
基金项目
大连医科大学附属第二医院交叉学科创新项目(2022JCXKYB21)
大连医科大学附属第二医院交叉学科创新项目(2022JCXKYB01)
国家自然科学基金(123374174)
国家自然科学基金(12374253)
国家自然科学基金(12004064)
国家自然科学基金(12074053)
中央高校基本科研业务费专项(DUT22LK11)
中央高校基本科研业务费专项(DUT22QN207)
DUT-BSU联合研究所国际合作研究基金(ICR2202)
维普
万方数据