|
This article by chemical vapor deposition method were prepared SnO 2 the nanowires and NI x < / sub> the Sn 1 - x O 2 -δ was < / sub> nanowires and nanobelts samples , explore the Curie point above room temperature diluted ferromagnetic semiconductor nanowire preparation method and process conditions ; using X-ray diffraction ( XRD ) , selected area electron diffraction ( SAED ) , scanning electron microscopy (SEM), X -ray energy dispersive spectroscopy (EDS), transmission electron microscopy ( TEM ) , vibrating sample magnetometer meter ( VSM ) , photoluminescence the spectrometers ( PL ) , X - ray photoelectron spectroscopy (XPS) characterization methods carry out a systematic study of the samples , a detailed study of the micro- structure of the sample , morphology , and magnetic , and its growth mechanism and magnetic sources . The main conclusions are as follows : using catalyst auxiliary SnO 2 nanowires sample is deposited on the Si substrate , smooth surface , the diameter distribution of between 40-150nm , no significant change in diameter in the axial direction , length greater than 20 microns, a single crystal. 2 using a chemical vapor deposition method , is deposited on the Si substrate a the of Ni x nanowires of Sn 1 - x O 2- delta and nano The tape sample , the diameter of the nanowire is between 30nm-150nm , the feature size of 50nm, nanobelts feature size of a thickness of 33nm , a width of 170nm and length greater than 2 microns, and monocrystalline . 3 . Discuss the growth mechanism of nanowires and nanobelts , gas - liquid - solid mechanism to control its growth , and by increasing the thickness of the gold layer sample preparation method to capture the small droplets separatist details . 4 . The Ni x Sn 1- x < / sub > O 2 -δ nanowires and nanobelts sample magnetization curve at room temperature can be observed to the obvious hysteresis , indicating that the samples have room temperature ferromagnetism , the magnetic moments of up to 3.33μ B / Ni, and with the increased incorporation magnetic moment first and then drop . By XRD test did not find the Ni single quality or oxide peak , also found no magnetic clusters and transmission electron microscopy observation photos XPS demonstrated that Ni ion states that Ni ions instead of SnO 2 Sn ions in the crystal lattice , rather than Ni clusters or heteroaryl phase. Samples at room temperature ferromagnetism is intrinsic . 6 samples of magnetic sources can be bound by oxygen vacancy type model explains magnetopolaron .
|