下一代高密度磁记录介质——L10FePt、CoPt研究进展

垂直磁记录是现今主要的信息存储技术.当前以CoCrPt为记录介质的垂直磁记录已达到密度极限,进一步提高记录密度需要采用磁晶各向异性能更高的材料.L10 FePt、CoPt被认为是下一代高密度磁记录的理想介质材料.本文系统综述了L10 FePt、CoPt记录介质的研究进展.     

几种新型的磁记录介质

目前磁记录技术的发展遇到了瓶颈,记录密度达到了极限.继续提高记录密度需要采用具有超高磁晶各向异性的记录介质材料,但这些材料的矫顽力巨大,使得数据的写入困难.为了摆脱这种困境,科研工作者提出了几种新型的磁记录介质的概念如倾斜介质、梯度介质、渗透垂直介质,并开展了相应的研究.本文综述了这几种新型的磁记录介质的研究进展.     

Microstructure and electrochemical properties of melt-spun Nd_(0.8)Mg_(0.2)(Ni_(0.8)Co_(0.2))_(3.8) hydrogen storage alloy

The effects of rapid solidification on the microstructure and electrochemical properties of Nd0.8Mg0.2(Ni0.8Co0.2)3.8 alloy were systematically investigated.The microstructure of alloys was characterized by scanning electron microscopy(SEM),X-ray diffractometer(XRD) and transmission electron microscopy(TEM).It was found that the melt-spun Nd0.8Mg0.2(Ni0.8Co0.2)3.8 ribbons became thinner and the average grain size of the ribbons became smaller with increasing wheel speed.A fraction of amorphous phase was observed for the ribbons melt-spun at high wheel speed(≥20 m/s).Microstructural characterization revealed that two phases:(Nd,Mg)2(Ni,Co)7 main phase(Ce2Ni7 type structure) and NdNi5 second phase(CaCu5 type structure),existed in the samples in cast state and melt-spun.The cycle stability of the melt-spun alloys was significantly enhanced as compared with cast alloy,and the sample prepared at wheel speed of 20 m/s exhibited good comprehensive electrochemical properties.     

耐高温射线屏蔽材料的制备及性能

核能应用技术的发展对射线屏蔽材料提出了耐高温、抗辐照等要求.氢化锆因其高的氢含量和在高温、射线辐照下的结构稳定性被认为是优良的快中子屏蔽材料,但难以制成大尺寸块体.研究了氢化锆与金属基体材料的反应,采用粉末冶金法获得了对快中子、热中子和γ射线均具有显著屏蔽效果的致密块体屏蔽材料.该材料在600℃仍不会明显脱氢,是一种综...