Anisotropic thick film magnets prepared by high-speed PLD method and their application to an advanced and small motor

在本研究中，利用添加剂改善了各向异性和各向同性Nd-Fe-B薄膜磁体的磁性能。此外，还研究了该薄膜的几种应用。所得结果如下：(1)各向异性Nd-Fe-B薄膜，得到了由Nd_<2.4>Fe_<14>B+Ga_<0.5at制备的薄膜。%>靶的矫顽力、剩余物和（BH）_<max>值分别约为850 kA/m、0.95 T和150 kJ/m^3。这些磁性能优于无添加剂的各向异性pld制备的Nd-Fe-B薄膜。我们还证实了膜的c面（004）、（006）和（008）对应的x射线衍射峰的强度比无添加剂膜的强。(2)各向同性薄膜磁体分别以Zr、Nb和Ga为靶材制备了各向同性Nd-Fe-B厚膜磁体。分别采用常规退火（CA）和脉冲退火（PA）两种退火方法进行结晶。在使用Nd_<2.6>Fe_<14>B目标的情况下，0.5 at。Zr、Nb和Ga的加入使薄膜的矫顽力比CA法制备的样品提高了约100~300 kA/m。我们还证实了PA法进一步提高了薄膜的矫顽力，得到了由Nd_<2.6>Fe_<14>B+Ga_<0.5at制备的薄膜。%>靶具有较大的矫顽力，约为1700 kA/m。(3)应用我们将上述薄膜应用于摩擦驱动电机和毫米级电机。

In the study, an improvement in magnetic properties of anisotropic and isotropic Nd-Fe-B film magnets was carried out by using additives. In addition, several applications comprising the films were investigated. The obtained results are as followed.(1) Anisotropic Nd-Fe-B filmsAn obtained film prepared from the Nd_<2.4>Fe_<14>B+Ga_<0.5at.%> target had the coercivity, remanence and (BH)_<max> values of approximately 850 kA/m, 0.95 T and 150 kJ/m^3, respectively. These magnetic properties are superior compared with those for the anisotropic PLD-made Nd-Fe-B films without additives. We also confirmed that the intensities of a X-ray diffraction peaks corresponding to the c-planes such as (004), (006) and (008) of the film were stronger than those of the additive-free film.(2) Isotropic film magnetsPLD-made isotroipic Nd-Fe-B thick film magnets were prepared from targets with Zr, Nb and Ga, respectively. They were crystallized by two annealing methods of conventional annealing (CA) and pulse annealing (PA), respectively. In the case of using Nd_<2.6>Fe_<14>B targets, 0.5 at.% Zr, Nb and Ga addition increased the coercivity of the film by approximately 100～300 kA/m compared with that of additive-free samples prepared by CA method. We also confirmed further increase in coercivity of the film by PA method and the obtained film prepared from a Nd_<2.6>Fe_<14>B+Ga_<0.5at.%> target had large coercivity of approximately 1700 kA/m.(3) ApplicationsWe applied the above-mentioned films to a friction-drive motor and a milli-size motor.