PREPARATION OF PERPENDICULAR MAGNETIC RECORDING MEDIA BY ELECTROLESS PLATING METHOD

在垂直磁记录系统高密度磁记录介质应用的基础上，研究了化学镀法制备高性能薄膜的形成及性能评价。采用CoNiReP和CoNiReMnP合金的钴合金镀膜实现了垂直各向异性薄膜。此外，通过新型化学镀液制备了适合垂直记录的三元CoNiP合金。采用结晶型和非晶型NiP衬底的钴合金记录介质分别表现出所谓的双层（增强输出电压）和增强钴合金结晶度的效果，从而能够记录更高的密度。当使用NiWP镀底层时，产生了这两种效果，并且在含有NiWP底层的钴合金介质中建立了第三峰300kFRPI输出信号的极高记录密度。确定下层最合适的厚度为300a的薄层。使用NiMoP下层时，钴合金介质自动形成初始软层，初始软层的厚度由NiMoP下层的Mo浓度控制。通过SEM、TEM、RHEED和极局部EDX等分析技术，并结合湿法刻蚀法，提出镀层结构是富Co区磁性部分分散在非晶NiP结构非磁性部分的偏析沉积条件。这种分离条件可以增强磁畴的隔离性，使记录更高的磁记录密度成为可能。最后，提出了环形磁头组合垂直磁记录介质的指导原理。

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.