Đang chuẩn bị liên kết để tải về tài liệu:
Báo cáo hóa học: " Synthesis and magnetic properties of Zr doped ZnO Nanoparticles"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Synthesis and magnetic properties of Zr doped ZnO Nanoparticles | Zhang et al. Nanoscale Research Letters 2011 6 587 http www.nanoscalereslett.eom content 6 1 587 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Synthesis and magnetic properties of Zr doped ZnO Nanoparticles Jing Zhang Daqiang Gao Guijin Yang Jinlin Zhang Zhenhua Shi Zhaohui Zhang Zhonghua Zhu and Desheng Xue Abstract Zr doped ZnO nanoparticles are prepared by the sol-gel method with post-annealing. X-ray diffraction results show that all samples are the typical hexagonal wurtzite structure without any other new phase as well as the Zr atoms have successfully entered into the ZnO lattices instead of forming other lattices. Magnetic measurements indicate that all the doping samples show room temperature ferromagnetism and the pure ZnO is paramagneism. The results of Raman and X-ray photoelectron spectroscopy indicate that there are a lot of oxygen vacancies in the samples by doping element of Zr. It is considered that the observed ferromagnetism is related to the doping induced oxygen vacancies. Keywords Zn1-xZrxO nanoparticles Room temperature ferromagnetism Oxygen vacancies Introduction Diluted magnetic semiconductors DMSs have attracted intense interest due to their potential applications in spintronic devices 1-3 . DMSs are usually produced by doping semiconductors with transition metals TMs . Through theoretically predicting GaN and ZnO as typical n-type semiconductors would be ideal candidates for room-temperature RT DMSs 4 . The room temperature ferromagnetism RTFM in TM-doped GaN has been reported in experiment and theroy such as Mn 5 6 Gd 7 and Cr 8 9 . Compared with GaN ZnO has a lot of outstanding superiorities as is known to all which has a wide band-gap 3.37 eV at RT and a high excitation binding energy 60 meV at RT so ZnO has been got more and more attention. Otherwise since Dietl et al. predicted that Mn-doped ZnO can show the clear RTFM and also has a higher Curie temperature TC than RT 10 which triggered worldwide .