Abbas Syed Kumail, Atiq Shahid, Saleem Murtaza, Riaz Saira, Naseem Shahzad, Anwar M Sabieh
Centre of Excellence in Solid State Physics, University of the Punjab Lahore-54590 Pakistan
Department of Physics, Syed Babar Ali School of Science and Engineering (SSE), Lahore University of Management Sciences (LUMS) Opposite Sector U, D.H.A. Lahore 54792 Pakistan.
RSC Adv. 2019 Jun 4;9(31):17581-17590. doi: 10.1039/c9ra03295a.
One-dimensional nanorod arrays exhibiting hierarchical flowerlike morphologies, of Co and Ni based ferrites were synthesized by hydrothermal treatment and using ammonium fluoride (NHF) as a mineralizing agent. The effects of NHF concentration and synthesis temperature were probed to control the morphology of these nanorods that were formed as a result of crystal nucleation. It was observed that a higher concentration of NHF leads to several other nucleation sites above these nanorods while controlled concentration of precursors and NHF results in the synthesis of floral patterns. The specific geometries of these nanorods leads to a shape anisotropy effect resulting in increased magnetic coercive fields. To study the effect of magnetic field on the resistance and current density, impedance spectroscopy and -- characteristics, respectively, were performed. Nanorods show enhanced values for resistance with the increase in magnetic field confirming the effect of magnetoresistive coupling while a decrease in current densities with increasing magnetic field highlights the potential of these structures for magnetoresistive applications.
通过水热法并使用氟化铵（NHF）作为矿化剂，合成了具有分级花状形态的一维钴和镍基铁氧体纳米棒阵列。探究了NHF浓度和合成温度对这些因晶体成核而形成的纳米棒形态的影响。观察到较高浓度的NHF会导致这些纳米棒上方出现其他几个成核位点，而前驱体和NHF的受控浓度则导致花状图案的合成。这些纳米棒的特定几何形状导致形状各向异性效应，从而增加了磁矫顽场。为了研究磁场对电阻和电流密度的影响，分别进行了阻抗谱和 - 特性测试。纳米棒随着磁场增加显示出电阻值增强，证实了磁阻耦合效应，而随着磁场增加电流密度降低突出了这些结构在磁阻应用方面的潜力。
