台式动量分辨声子光谱学：通过X射线漫散射解锁晶格动力学
Benchtop Momentum-Resolved Phonon Spectroscopy: Unlocking Lattice Dynamics via X-ray Diffuse Scattering
- Institute of Physics, University of São Paulo（圣保罗大学物理研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
该研究开发了一种基于台式SAXS/WAXS仪器的方法，可通过TDS图案提取IFCs以获取全布里渊区声子信息，实现低成本的晶格动力学表征。
AI中文摘要：
动量分辨声子光谱对于理解材料的热学、电子和结构性质至关重要，但传统上需要使用大型同步加速器或中子设施。我们报告了一种范式转变，证明可使用商用台式小角/广角X射线散射（SAXS/WAXS）仪器对热漫散射（TDS）图案进行精确测量和定量分析。通过利用低能（8 keV）X射线源和定制集成的真空几何结构，我们获取了硅（111）和（100）晶片的特征TDS图案。我们证明这些台式图像包含足够的信息，可通过全局优化算法提取原子间力常数（IFCs），达到与含统计噪声的模拟数据拟合精度相当的水平。至关重要的是，此能力可获取整个布里渊区的声子信息，这是标准实验室技术（如一阶拉曼光谱）无法实现的晶格动力学关键组成部分。这种低门槛方法使几乎任何研究实验室都能获得同步加速器级别的晶格动力学表征，为研究新兴材料体系中的本征应变和各向异性晶格动力学开辟了新途径。
英文摘要：
Momentum-resolved phonon spectroscopy is essential for understanding the thermal, electronic, and structural properties of materials, yet it traditionally necessitates access to large-scale synchrotron or neutron facilities. We report a paradigm shift by demonstrating the accurate measurement and quantitative analysis of Thermal Diffuse Scattering (TDS) patterns using a commercially available benchtop Small/Wide-Angle X-ray Scattering (SAXS/WAXS) instrument. By utilizing a low-energy (8 keV) X-ray source and a custom-integrated vacuum geometry, we acquired characteristic TDS patterns in silicon (111) and (100) slabs. We demonstrate that these benchtop images contain sufficient information to extract interatomic force constants (IFCs) through global optimization algorithms, achieving a fitting accuracy comparable to those obtained from simulated data with statistical noise. Crucially, this capability provides access to phonon information across the entire Brillouin Zone, a critical component of lattice dynamics unavailable via standard laboratory techniques like first-order Raman spectroscopy. This low-barrier approach makes synchrotron-level lattice dynamics characterization accessible to virtually any research laboratory, enabling new avenues for the study of intrinsic strain and anisotropic lattice dynamics in emerging material systems.
