The Study Of Microstructure And Magnetic Properties Of Co And CoCr Nanowire Arrays

In this article,fristly the highly ordered anodic aluminum oxide(AAO) templates have been fabricated by two-step anodization method,then Co and CoCr magnetic nanowire arrays were fabricated by ac electrodeposition in different conditions.Anodic aluminum oxide with highly ordered self-organized nanopore array structure,with high-density,diameter and depth easy controled and vertical membrane surface hexagonal nano-holes,that can act as a "mold" when fabricat nanowires.In this experiment,highly ordered anodic aluminum oxide templates with a diameter of about 40nm have been fabricated by two-step anodization method.Co magnetic nanowire arrays that Anodic aluminum oxide as template were fabricated by ac electrodeposition in different conditions.The main study was the effect of magnetic field and pH value on microstructure and magnetic properties of Co nanowire arrays.That have been deposited in both cases of without magnetic field and 0.3T magnetic field which along nanowires length direction that the PH value is 60 The magnetic hysteresis loops were measured at room temperature show that magnetic field lead the coercivity parallel to the direction of nanowire were increase from 1100Oe to 1830Oe.the XRD patterns show that the microstructure chang from (10(?)0) texture to(10(?)1) texture.Then Co nanowire arrays have been deposited in the same situation that the pH value is 6.5.Magnetic hysteresis loops show that magnetic field lead the coercivity parallel to the direction of nanowire were increase from 1590Oe to 1960Oe.the XRD patterns show that the microstructure chang from (10(?)0) texture to(10(?)1) texture,and appear(0002) texture.The experimental results show that magnetic field and the pH value lead to Co nanoparticles Growth-oriented.By research on the relationship between the coercivity measured at different angle and angle,We believe that the magnetization reversal process of Co Nanowires is Non-coherent magnetization reversal process.CoCr nanowire arrays were fabricated through the same method.we focus on the effect of magnetic field and heat treatment on microstructure and magnetic properties of CoCr nanowire arrays.CoCr nanowire arrays have been deposited in both cases of without magnetic field and 0.3T magnetic field which along nanowires length direction,magnetic hysteresis loops of the two samples show that the coercivity in both parallel and vertical direction of nanowire has little change,the XRD patterns show that the CoCr nanowire no diffraction peak for amorphous.In order to study CoCr nanowires deeply,the samples were heat treatment under strong magnetic field in different temperatures such as 350C°,450C°,550C°and650 C°.Experimental data show that there are major changes of the magnetic properties before and after heat treatment at different temperatures,the coercivity were increase from 1200Oe to 1800Oe-2000Oe.