Analysis of grain boundaries in CoCrTa and CoPtCrB HDD media by analytical transmission electron microscopy.
Analysis of grain boundaries in CoCrTa and CoPtCrB HDD media by analytical transmission electron microscopy.
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通过分析透射电子显微镜分析 CoCrTa 和 CoPtCrB HDD 介质中的晶界。
DOI：
10.1093/jmicro/dfh047
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
S. Takeda
中科院分区：
文献类型：
--
作者：
K. Shoda;T. Matsubara;S. Takeda
用透射电子显微镜（TEM）分析了CoCrTa和CoPtCrB两种钴基硬盘介质的晶体结构和晶界元素分布。CoCrTa介质具有六方密堆积结构的具有极度扭曲的（0002）平面的晶粒边界。通过高分辨率TEM（HRTEM）成像获得的1.5 nm的晶界宽度与通过能量色散谱（EDS）映射获得的1.5 nm的晶界宽度一致。EDS分析表明，Cr偏聚到晶界，而Ta不偏聚到晶界或晶粒。钴保留在晶粒内。CoPtCrB介质具有无定形晶界和晶粒中的斑点。EDS和电子能量损失谱分析表明，Cr和B均偏聚在晶界和斑点上。Co和Pt都保留在晶粒内。高分辨透射电镜（HRTEM）得到的0.4 nm的晶界宽度与高角度暗场扫描TEM得到的1.5 nm的晶界宽度不同，前者为晶体学晶界，后者为磁性晶界，这与HDD介质的磁性显著相关。
Crystallographic structures and elemental distributions of grain boundaries in cobalt (Co)-based hard disk drive (HDD) media of CoCrTa and CoPtCrB were analysed by analytical transmission electron microscopy (TEM). CoCrTa medium had crystalline grain boundaries with extremely distorted (0002) planes of hexagonal close-packed structure. The width of grain boundaries of 1.5 nm obtained by high-resolution TEM (HRTEM) imaging agreed with that of 1.5 nm obtained by energy-dispersive spectroscopy (EDS) mapping. The EDS analysis revealed that Cr was segregated to grain boundaries while Ta was not segregated to either grain boundaries or grains. Cobalt was retained within grains. CoPtCrB medium had amorphous grain boundaries and spots in grains. The EDS and electron energyloss spectroscopy analyses revealed that both Cr and B were segregated to grain boundaries and spots. Both Co and Pt were retained within grains. The width of the boundaries of 0.4 nm obtained by HRTEM differed from that of 1.5 nm obtained by high-angle angular dark-field scanning TEM; the former indicates the crystallographic boundary and the later corresponds to the magnetic boundary, which is significantly correlated to the magnetic properties of HDD media.