Ru掺杂对闪锌矿ZnO磁光机理的影响

Effect of Ru doping on the magnetic and optical properties of zinc-blende ZnO

采用第一性原理方法,计算了Ru掺杂量为3.125 mt%—9.375 mt%范围内闪锌矿ZnO的电子结构、磁性参数和光学性质.计算结果表明,Ru掺杂量越高,体系的形成能越低,掺杂越容易,体系稳定性越高.Ru掺杂量为3.125 mt%时,体系表现出铁磁性;Ru掺杂量为6.25 mt%时,Ru-Ru间距为0.5671 nm的体系表现出铁磁性,Ru-Ru间距为0.4630 nm的体系表现出反铁磁性;Ru掺杂量为9.375 mt%时,体系表现出亚铁磁性.铁磁性系统的Ru-4d态在费米能级附近发生了明显的自旋劈裂效应,磁矩主要来源于Ru-4d态和O-2p态.上述特性说明,通过控制Ru在ZnO中的掺杂方式以及浓度,可以实现体系磁性的转变.在红外和远红外区域,掺杂对光学性质有较为显著的影响,各个掺杂方式均使该区域的吸收系数和反射率显著增大.这表明Ru掺杂闪锌矿ZnO可应用于磁、光一体的半导体材料.

Based on first-principles,the electronic structures,magnetic and optical properties of Ru-doped zinc-blende ZnO are calculated in the doping range of 3.125 mt%-9.375 mt%.According to the results,as the doping concentration of Ru increases,the formation energy of the system gets lower and lower,which indicates that the stability of the system increases and the doping becomes easier.The system exhibits ferromagnetism in case of 3.125 mt%Ru-doped structure.For 6.25 mt%Ru-doped structure,the systems containing two Ru atoms with the Ru-Ru distances of 0.5671 nm and 0.4630 nm exhibit ferromagnetism and antiferromagnetism,respectively.The system exhibits ferrimagnetism in case of 9.375 mt%Ru-doped structure.There is an obvious spin splitting effect of Ru-4 d state of ferromagnetic system near the Fermi level,and the magnetic moments are mainly induced by the Ru-4 d states and O-2 p states.The above characteristics show that the transformations of ferromagnetism,antiferromagnetism and ferrimagnetism can be realized by controlling the doping mode or the doping concentration.In the infrared and far infrared regions,doping has the greatest influence on the optical properties.Most doping methods significantly increase the absorption coefficient and reflectivity of this region.This shows that Ru doped zinc-blende ZnO is expected to become a semiconductor material integrating magnetism and optics.