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La -doped and Cu -doped ZnO nanowires have been prepared to compare the substitution effect on the microstructural and magnetic properties. The XRD patterns of both compositions with single diffraction peak (002) show the same wurtzite hexagonal structure. The growth rate of the ZnO nanowires were enhanced by Cu doping, which were different from the suppression of growth rate by La doping. Room temperature ferromagnetism is observed for all ZnO , Cu -doped ZnO and La -doped ZnO nanowires. The saturation magnetizations are 0.102, 0.232 and 0.04 emu/g for ZnO , Cu -doped ZnO and La -doped ZnO nanowires, respectively. The results showed that the ferromagnetism is restrained by Cu doping, but enhanced by the La doping.

This report proposes a graphical-like approach for simulating the Hamiltonian of the t–J model. The two spin states are modeled by the two emitting layer, the kinematics of the electrons and the causalities between the operators are satisfied through the event cone. Operators and the event cone are integrated together, and the results indicate that this approach can provide information during the evolution of the t–J model. In addition, parameters that can be accessed by this approach are consistent with general requirements on values of t and J in the t–J model. Furthermore, our approach also includes the solution with vanishing hopping amplitude (tij = 0) and the H∞ solution.