Fabrication of high-potential nanocomposite magnets by controlling crystallite orientation

1.高取向SmFe_(12)/α-Fe纳米复合薄膜的制备我们成功地制备了一系列由c轴取向的SmFe_(12)和α-Fe(软磁相)组成的纳米复合薄膜，并研究了取向度与磁性能的关系。(1)，亚/钛/(SmFe；12&gt；，αFe)/Ti薄膜：虽然在整个α-Fe组分VFe范围内都获得了交换耦合纳米复合薄膜，但随着V_&lt；Fe&gt；的增加，SmFe_&lt；12&gt；的取向已经从(001)织构转变为(101)和(001)的混合织构。在V&lt；Fe&gt；=6%附近，Hc和最大能积(BH)_&lt；max&gt；均出现极大值。(2)，亚/(SmFe；12&t；，α-Fe)/Ti薄膜：通过去除Ti底层，我们首次成功地制备了高度取向的SmFe_(12)/α-Fe纳米复合薄膜，其中(001)织构保持了V_&lt；Fe&gt；-50%的织构。HC和(BH)_lt；max&>；都在V_&lt；Fe&>；25%附近取最大值，其中(BH)_…获得了20 MGOe的更多&lt；max&gt；(3)为了分析磁性的来源，特别是Hc增加的原因，我们进行了微磁计算，并与实验进行了比较。我们发现，用硬相间的弱交换耦合和软硬相间的强耦合参数可以解释观察到的H_c的V&lt；Fe&gt；关系。为了在块体纳米复合样品中定向硬磁相的易轴，我们研究了高场退火对非晶薄带晶化的影响。非晶薄带由Nd2(Fe_&lt；1-x&gt；Co_x)14B作为硬相，(Fe_&lt；1-x&gt；Co_x)作为软相。结果表明，当退火温度低于硬质相的居里温度时，硬质相的体积分数在100kOe的场下大于零场。到目前为止，还没有观察到与随机排列的任何显著偏差

1. Fabrication of highly-oriented SmFe_<12>/alpha-Fe nanocomposite filmsWe have successfully fabricated a series of nanocomposite films composed of c-axis oriented SmFe_<12> (hard magnetic phase) and alpha-Fe (soft phase), and investigated the relation between the degree of orientation and magnetic properties. (1), sub/Ti/(SmFe_<12>, alphaFe)/Ti films : Although exchange-coupled nanocomposite films have been obtained over the entire range of alpha-Fe fraction VFe, the orientation of SmFe_<12> has been changed from (001)-texture to the mixture of (101) and (001) textures with increasing V_<Fe>. Both coercive force Hc and maximum energy product (BH)_<max> took a maximum around V_<Fe>=6%. (2), sub/(SmFe_<12>, alpha-Fe)/Ti films : By removing the Ti underlayers, we have for the first time succeeded to fabricate the highly-oriented SmFe_<12>/alpha-Fe nanocomposite films, in which(001)-texture has been kept up to V_<Fe>-50%. Both Hc and(BH)_<max> took a maximum around V_<fe> 25%, where (BH)_ … More <max> of 20 MGOe was obtained. (3), In order to analyze the origin of the magnetic properties, especially of the Hc increase, we have made a micromagnetic calculation and compared it with the experiment We then found that observed V_<Fe> dependence of H_c could be explained by using parameters of the weak exchange-coupling between hard phases and strong coupling between soft-hard phases.2. Fabrication of Nd-Fe-Co-B nanocomposite ribbons by high-field-annealingIn order to orient the easy axis of hard magnetic phase in bulk nanocomposite samples, we have investigated the effect of high-field annealing on the crystallization of amorphous ribbons, composed of Nd2(Fe_<1-x>Co_x)14B as a hard phase and (Fe_<1-x>Co_x) as a soft phase. It is found that, when the annealing temperature is below the Curie temperature of the hard phase, the volume fraction of the hard phase is larger in the field of 100 kOe than that in zero field. Any significant deviation from the random alignment has not been observed up to now Less