采用磁控溅射技术制备了系列Si(111)/Cr(10 nm)/NdCo_x(400 nm)/Cr(10 nm)薄膜，其中，Co/Nd原子比x=2.5~7.2。利用XRD、SEM、AFM/MFM、VSM等手段研究了Nd含量对制备态薄膜垂直磁各向异性(PMA)与磁畴结构及退火态薄膜相结构与磁性的影响规律。结果表明，随着Nd含量的变化，制备态Nd-Co薄膜的垂直磁各向异性能K_u在x=5.2附近存在一个较宽的峰，峰值处K_u=(80±5) kJ/m³。MFM图像的相移均方根偏差(Δ?_rms)在临界成分x=5.2处也存在最大值，其成分依赖关系与K_u-x的变化趋势一致。薄膜应力诱导的磁弹各向异性是导致溅射Nd-Co非晶薄膜PMA的主要原因。经过在600 ℃真空快速退火后，所有薄膜均析出了Nd₂Co₁₇、NdCo₂、Nd₄Co₃等金属间化合物，而NdCo_5±x相纳米晶只在Nd过量(至少4%，原子分数)的x=2.5和3.8薄膜中才被观测到，同时还伴随着Nd₂Co₇共生相的析出。室温磁性测试结果表明，NdCo_5±x和Nd₂Co₇相纳米晶的析出，导致x=2.5和3.8薄膜面内矫顽力(分别为H_c-in=54和51 kA/m)显著增强；而x≥4.4样品的面内矫顽力保持在低值(H_c-in=4~8 kA/m)范围内。

A series of Si(111)/Cr(10 nm)/NdCo_x(400 nm)/Cr(10 nm) thin films with the atomic ratio of Co/Nd (x) varying from 2.5 to 7.2 were prepared by radio frequency magnetron sputtering. The influence of Nd content on the structure and magnetic properties of the as-prepared and post annealed films were investigated by XRD, SEM, VSM and AFM/MFM. Magnetic measurements at room temperature show that the compositional variation of the perpendicular anisotropy energy (K_u) exhibits a broad peak around x=5.2 with maximum of K_u=(80±5) kJ/m³ for the as-prepared Nd-Co amorphous films. MFM characterization shows that the root mean square deviation of phase shift in MFM images (Δ?_rms) also have a compositional dependence which is similar to that of K_u-x. The experimental results show that the stress induced magneto-elastic anisotropy is the primary origin of the perpendicular magnetic anisotropy (PMA) in the as-prepared Nd-Co amorphous film. After rapid thermal annealing (RTA) process in a vacuum atmosphere at 600 °C, intermetallic compounds such as Nd₂Co₁₇, Nd₄Co₃ and NdCo₂ are precipitated in all the studdied films, while NdCo_5±x nanocrystals accompanied by the precipitation of Nd₂Co₇ symbiotic phase were observed only in the films with x=2.5 and 3.8 (the atomic fraction of Nd excesses at least 4%). The in-plane coercivity of the films with x=2.5 and 3.8 was significantly enhanced (H_c-in=54, 51 kA/m) due to the precipitation of NdCo_5±x and Nd₂Co₇ nanocrystals, while that of the samples with x>4.4 remained low value (H_c-in=4~8 kA/m).