PREPARATION OF PERPENDICULAR MAGNETIC RECORDING MEDIA BY ELECTROLESS PLATING METHOD

在高密度磁记录介质垂直磁记录系统中应用的基础上，研究了化学镀方法制备高性能薄膜的方法及其性能评价。垂直各向异性薄膜是通过CoNiReP和CoNiReMnP合金的钴合金电镀膜实现的。此外，通过一种新的化学镀液，研制出了适用于垂直记录的三元CoNiP合金。具有晶化和非晶态NiP底层的钴合金记录介质分别表现出所谓的双层(提高输出电压)和提高钴合金结晶度的效应，从而能够记录更高的密度。当使用NiWP电镀底层时，这两种效应都产生了，并且通过含有NiWP底层的钴合金介质建立了很高的记录密度，如第三峰的300kFRPI输出信号。采用NiMoP作底层时，钴合金介质会自动形成一个初始软化层，初始软化层的厚度由NiMoP底层中的Mo浓度控制。结合扫描电子显微镜、透射电子显微镜、RHEED和极局域能谱等分析技术，并结合湿法腐蚀的方法，认为镀态介质的结构是富Co区的磁性部分分散在非晶态NiP结构的非磁性区域的偏析沉积条件。这种隔离条件可以增强磁畴的隔离，使记录更高的磁记录密度成为可能。最后，我们提出了环型磁头组合的垂直磁记录介质的指导原则。

The formation and evaluation on high function thin films by an electroless plating method were studied on the basis of the application of them to high density magnetic recording media of perpendicular magnetic recording system. The perpendicular anisotropy thin film is realized by the cobalt alloy plating films of CoNiReP and CoNiReMnP alloys. Moreover, the ternary CoNiP alloy suitable for perpendicular recording was finally developed by a new electroless plating bath. The cobalt alloy recording media with the underlayer of crystallized and amorphous NiP underlayers show the effects of so-called double layer (enhancement of output voltage) and of enhancing crystallinity of cobalt alloy which was able to record the higher density, respectively. When using NiWP plating underlayer, the both effects are produced and the very high recording density such as 300kFRPI output signal of the third peak is established by the cobalt alloy media with NiWP underlayer. The most suitable thickness of the underlayer is confirmed to be so thin layer of 300 A. Moreover when using NiMoP underlayer, the cobalt alloy medium is automatically formed with an initial soft layer and the thickness of the initial soft layer is controlled by the Mo concentration of NiMoP underlayer.With some analytical techniques of SEM, TEM, RHEED and very local area EDX, and also with a combination of wet etching method with them, the structure of the plated media is suggested to be the segregated deposition conditions that the magnetic parts of Co rich area are scattered in the non-magnetic area of an amorphous NiP structure. Such an segregated condition can enhance an isolation of magnetic domains and it makes it possible to record the higher magnetic recording density.Finally, we proposed a guiding principle of perpendicular magnetic recording media with a combination of ring-type head.