Li Hua, Xu Cai-Ling, Zhao Guang-Yu, Li Hu-Lin
College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P.R. China.
J Phys Chem B. 2005 Mar 10;109(9):3759-63. doi: 10.1021/jp045347t.
Co49Pt51 nanowire arrays with an average diameter of 35 nm and lengths up to several micrometers were grown in an ordered porous anodic aluminum oxide (AAO) template using direct-current electrodeposition. The as-deposited samples were annealed at 100, 200, 300, 400, 500, 600, and 700 degrees C, respectively. The temperature dependence of the magnetic property of the Co49Pt51 nanowire arrays associated with the microstructure was analyzed by X-ray diffraction and a vibrating sample magnetometer. Magnetic measurements show that the samples both as-prepared and annealed at low temperatures have excellent perpendicular anisotropy. The perpendicular coercivity (Hc(perpendicular)) of Co49Pt51 alloy nanowire arrays increases dramatically as the annealing temperature (T(A)) rises, reaches a maximum(Hc(perpendicular) = 2770 Oe) at 400 degrees C, and then decreases sharply as T(A) rises further. This phenomenon should be attributed to the special structure of the nanowire arrays/AAO, and the microstructure factors significantly change during the annealing process.
采用直流电沉积法，在有序多孔阳极氧化铝（AAO）模板中生长出平均直径为35 nm、长度达数微米的Co49Pt51纳米线阵列。将沉积后的样品分别在100、200、300、400、500、600和700摄氏度下退火。通过X射线衍射和振动样品磁强计分析了Co49Pt51纳米线阵列磁性能与微观结构的温度依赖性。磁性测量表明，制备态样品和低温退火样品均具有优异的垂直各向异性。Co49Pt51合金纳米线阵列的垂直矫顽力（Hc(垂直)）随着退火温度（T(A)）的升高而急剧增加，在400摄氏度时达到最大值（Hc(垂直)=2770 Oe），然后随着T(A)进一步升高而急剧下降。这种现象应归因于纳米线阵列/AAO的特殊结构，且在退火过程中微观结构因素发生了显著变化。
