首页|Lattice Dynamics of SnSe Single Crystals Studied by Inelastic Neutron Scattering Spectrometers at the China Advanced Research Reactor (CARR)
Lattice Dynamics of SnSe Single Crystals Studied by Inelastic Neutron Scattering Spectrometers at the China Advanced Research Reactor (CARR)
Wang, Prof. Hongliang Hao, Prof. Lijie Meng, Prof. Siqin Ma, Prof. Xiaoyan Li, Prof. Shiliang Wang, Prof. Jinchen Liu, Prof. Juanjuan Shen, Mr. Ao Gao, Dr. Jianxiang Duan, Miss Kexuan li, Dr. tianfu Sun, Prof. Kai Chen, Prof. Dongfeng 陈东风
Lattice Dynamics of SnSe Single Crystals Studied by Inelastic Neutron Scattering Spectrometers at the China Advanced Research Reactor (CARR)
Lattice Dynamics of SnSe Single Crystals Studied by Inelastic Neutron Scattering Spectrometers at the China Advanced Research Reactor (CARR)
摘要
Inelastic neutron scattering (INS) is a powerful nondestructive nuclear detection technique, which plays a unique role in probing the lattice dynamical properties of advanced functional materials. The China Advanced Research Reactor (CARR) neutron science platform is equipped with a suite of high-performance inelastic neutron scattering spectrometers, providing crucial technical support for condensed matter physics and material science research. In this work, high-quality single-phase SnSe thermoelectric single crystals were prepared via the temperature gradient method, and their crystal structure, phase purity and orientation were characterized by combining XRD, SEM/EDS and neutron single-crystal diffraction techniques. Utilizing three complementary INS spectrometers (BOYA, Bamboo and CIAE-JCNS) at CARR, the lattice dynamical behaviors of longitudinal and transverse acoustic phonons at the (400) crystal plane of SnSe were systematically investigated at room temperature. We clearly clarified the physical origin of scattering intensity asymmetry along the (H00) longitudinal direction, the implication of off-principal-axis signals in two-dimensional phonon maps, the lattice dynamical responses in the high-Q region, and the competitive relationship between neutron scattering cross-section enhancement and Debye-Waller factor attenuation. The obvious phonon energy softening, slope transition of acoustic phonon branches and sharp reduction of phonon lifetime in the high-energy region directly reveal the strong lattice anharmonicity and intrinsic structural anisotropy of SnSe, which is the microscopic root cause for its ultra-low lattice thermal conductivity. This work not only deepens the understanding of the phonon transport mechanism in SnSe thermoelectric materials, but also further validates the excellent performance and application potential of CARR inelastic neutron scattering spectrometers in the field of condensed matter characterization, enriching the application cases of nuclear scattering technology in advanced material research.
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