AI 中文总结
本研究发现热电半导体Mg3Sb2在压力下会发生金属化、超导转变及结构相变，明确其高压相图，为高压下热电材料研究提供见解。
AI 中文摘要
窄带隙热电（TE）材料的本征电子结构是研究高压下准粒子耦合效应的平台，可用于探索新型电子与声子输运、超导性及拓扑相变。本文报道在热电半导体Mg3Sb2中发现压力诱导的超导性：压力升高时，8.7 GPa发生金属化，随后伴随载流子类型从p型向n型转变的超导转变，该现象源于压力诱导的结构相变，从半导体相P-3m1转变为金属相C2/m-I。超导临界温度（Tc）呈圆顶状压力依赖关系，在12.6 GPa时峰值为3.3 K。结合理论计算、高压拉曼光谱及X射线衍射（XRD）测量，发现20 GPa以上存在额外结构相变，形成不同的C2/m-II相。本研究明确了Mg3Sb2的高压相图，阐明其压力依赖的电子性质，为未来高压下TE材料的研究提供重要见解。
英文摘要
The intrinsic electronic structures of narrow bandgap thermoelectric (TE) materials serve as a platform for the investigation of coupling effects of quasi-particles under high pressure, enabling the exploration of emerging electronic and phonon transport, superconductivity, and topological transition. Here, we report the discovery of pressure-induced superconductivity in the TE semiconductor Mg3Sb2. Upon the increased pressure, the metallization occurs at 8.7 GPa, followed by a superconducting transition concomitant with a carrier-type crossover from p- to n-type. This phenomenon arises from a pressure-induced structural phase transition from the semiconducting P-3m1 to the metallic C2/m-I phase. The superconducting critical temperature (Tc) exhibits a dome-shaped pressure dependence, peaking at 3.3 K at 12.6 GPa. Combined theoretical calculations, high-pressure Raman spectroscopy, and X-ray diffraction (XRD) measurements reveal an additional structural transition above 20 GPa, yielding a distinct C2/m-II phase. Our findings establish the high-pressure phase diagram of Mg3Sb2, elucidate its pressure-dependent electronic properties, and provide valuable insights for future investigations of TE materials under high pressure.
Comments18 pages,6 figures
Journal refJournal American Chemical Society (2026) 148 (25): 26481-26488
