Phonon Excitations in Pd40Ni40P20 Bulk Metallic Glass by Inelastic X-Ray Scattering
Phonon Excitations in Pd40Ni40P20 Bulk Metallic Glass by Inelastic X-Ray Scattering
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DOI：
10.4028/www.scientific.net/msf.879.767
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发表时间：
2016-11
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通讯作者：
S. Hosokawa;M. Inui;Y. Kajihara;T. Ichitsubo;K. Matsuda;H. Kato;A. Chiba;K. Kimura;K. Kamimura;S. Tsutsui;H. Uchiyama;A. Baron
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文献类型：
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作者：
S. Hosokawa;M. Inui;Y. Kajihara;T. Ichitsubo;K. Matsuda;H. Kato;A. Chiba;K. Kimura;K. Kamimura;S. Tsutsui;H. Uchiyama;A. Baron
为了研究Pd 40 Ni 40 P20块体金属玻璃的微观弹性性质，利用BL 35 XU/SPring-8高分辨率X射线散射谱仪对Pd 40 Ni 40 P20块体金属玻璃进行了非弹性X射线散射实验。清晰的纵向声学（LA）激发模式观察到在整个动量传递Q范围高达~22 nm-1。从色散关系的Q → 0极限得到的LA模式的微观声速比宏观值快约12%，这表明该BMG的弹性性质的微观不均匀性。此外，横向声学（TA）模式可以推导出从IXS光谱的详细分析。由TA模和LA模的激发能之比得到的微观泊松比为0.47 ± 0.04，大于宏观值0.40。因此，在宏观意义上已经发现的这种BMG的脆弱性在微观上得到了很大的增强。
To clarify microscopic elastic properties of a Pd40Ni40P20 bulk metallic glass, inelastic X-ray scattering (IXS) experiments were carried out using high-resolution IXS spectrometer installed at BL35XU/SPring-8. Clear longitudinal acoustic (LA) excitation modes are observed in the whole momentum transfer Q range up to ~22 nm-1. The microscopic sound velocity of the LA modes obtained from the Q → 0 limit of the dispersion relation is about 12% faster than the macroscopic value, suggesting the microscopic heterogeneity in the elastic properties of this BMG. In addition, transverse acoustic (TA) modes can be deduced from a detailed analysis of the IXS spectra. The microscopic Poisson’s ratio obtained from the ratio of the excitation energies of the TA and LA modes is 0.47 ± 0.04, larger than the macroscopic value of 0.40. Thus, the fragile nature of this BMG already found in the macroscopic sense is much enhanced in the microscopic view.