Two intermetallic FeAl compounds with Al content of 70.68 and 72.17 at% were studied using Mössbauer spectroscopy (5–296 K) and X-ray diffraction (15–300 K). The compounds were found to crystallize in the orthorhombic Cmcm space group (η-phase). The collected data revealed that dynamics of the Fe atoms (harmonic in entire temperature range) is significantly different that Al atoms. For the latter strong anharmonicity was evidenced. According to X-ray diffraction, the partial filling of the different Al sites leads to occurrence of low- and high-symmetry coordination of Fe atoms, which provides explanation of two doublets evidenced in collected Mössbauer spectra. All spectral parameters of the doublets as well as the Debye temperature, force constant, kinetic and potential energies of vibrations were determined. Those results revealed significant differences between both alloys, likely originating from approaching the stability boundary of the η-phase for Fe–Al 72.17 at% alloy.

用穆斯堡尔光谱法（5-296 K）和X射线衍射法（15-300 K）研究了两种金属间铝含量为70.68和72.17 at％的FeAl化合物。发现这些化合物在正交晶Ccm中结晶空间群（η相）。收集的数据表明，Fe原子的动力学（在整个温度范围内都是谐波的）与Al原子明显不同。对于后者，证明了强烈的非谐性。根据X射线衍射，不同Al位点的部分填充会导致Fe原子发生低对称和高对称配位，从而解释了在收集的Mössbauer光谱中发现的两个双峰。确定了双峰的所有光谱参数以及德拜温度，力常​​数，振动的动能和势能。这些结果表明两种合金之间存在显着差异，这很可能是由于接近Fe-Al 72.17 at％合金的η相稳定性边界所致。