Wei S, Li Z, Yin S, Zhang X, Liu W, Wang X
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, P.R. China.
J Synchrotron Radiat. 2001 Mar 1;8(Pt 2):566-8. doi: 10.1107/s0909049500018070.
XAFS has been used to investigate the local structure evolutions of ultrafine amorphous NiB alloy during the annealed crystallization process. A nanocrystalline Ni phase with the local structure of crystalline Ni-like and a crystalline Ni3B, have been produced for ultrafine amorphous NiB alloy under the annealed temperature of 573 K. The results rule out Rojo et al.'s devitrification mechanism of Ni80B20 amorphous alloy in which they considered that an amorphous pure Ni phase is formed in the first exothermic process. However, our results are almost identical with Riveiro et al.'s conclusion in which the intermediate state is interpreted as two metastable crystalline phases of Ni3B and Ni-rich NiB alloy. With the annealed temperature going onto 773 K, the ultrafine NiB sample is further decomposed and crystallized into crystalline Ni with long-range order.
X射线吸收精细结构光谱（XAFS）已被用于研究超细非晶态NiB合金在退火结晶过程中的局部结构演变。在573K的退火温度下，超细非晶态NiB合金产生了具有类晶体Ni局部结构的纳米晶Ni相和晶体Ni3B。结果排除了Rojo等人提出的Ni80B20非晶合金的失透机理，在该机理中他们认为在第一个放热过程中形成了非晶纯Ni相。然而，我们的结果与Riveiro等人的结论几乎一致，在该结论中，中间状态被解释为Ni3B和富Ni的NiB合金的两个亚稳晶相。随着退火温度升至773K，超细NiB样品进一步分解并结晶为具有长程有序的晶体Ni。
