Liangyan Chen*, Chao Fang and Weihua Liu Pages 287 - 297 ( 11 )
Background: Mn doped ZnSe low dimensional materials are attractive for different biological labels, gene silencing and dilute-magnetic device. ZnSe clusters are one of the basic building blocks of quantum dots and even cluster-assembled nanodevices, stable structures of undoped ZnSe clusters were established by previous pioneering work, and the Mn doped ZnSe clusters had been investigated, but the stable clusters in the ferromagnetic state have not been found yet.Objective: Our work is mainly based on Mn doped clusters (Mn2Zn10Se12) and C codoped clusters (Mn2Zn10CSe11) structure, magnetic properties through theoretical calculations. Methods: First principle density functional theory calculation with Dmol3 is used to execute all calculations. Results: Mn atoms prefer to substitute the nearest neighbor Zn atom sites in the rhombi part, and C atom prefers to occupy Se atom sites with shortest Mn-C bond length in Zn12Se12 nanocluster doping. Mn doped clusters (Mn2Zn10Se12) are in antiferromagnetic states and the most stable C codoped clusters (Mn2Zn10CSe11) are in ferromagnetic states. Magnetic behavior localized at the 3d orbitals of transitional metal Mn, 4p orbital of atom Se and 2p orbital of C atom. Mn2Zn10Se12 clusters are in antiferromagnetic states as the p-d hybridization introduced Mn-Mn superexchange mechanism. For the ferromagnetism of Mn2Zn10Se12 nanocluster, hole mediated double exchange mechanism introduced by C atom p-d hole state hybridization has been suggested. Conclusion: The codoping of C atom can stabilize the ferromagnetism of clusters through hole mediated double exchange mechanism, which may be meaningful for the exploring materials for cluster- assembled spin-electronic devices.
ZnSe clusters, doping, magnetism, structure, hole mediated, first principle calculation.
School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan, Hubei Province, School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan, Hubei Province, School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan, Hubei Province