Substitutional doping provides an effective strategy to tailor the properties of 2D materials, but it remains an open challenge to achieve tunable uniform doping, especially at high doping level. Here, uniform lattice substitution of a 2D Mo₂C superconductor by magnetic Cr atoms with controlled concentration up to ≈46.9 at% by chemical vapor deposition and a specifically designed Cu/Cr/Mo trilayer growth substrate is reported. The concentration of Cr atoms can be easily tuned by simply changing the thickness of the Cr layer, and the samples retain the original structure of 2D Mo₂C even at a very high Cr concentration. The controlled uniform Cr doping enables the tuning of the competition of the 2D superconductor and the Kondo effect across the whole sample. Transport measurements show that with increasing Cr concentration, the superconductivity of the 2D Cr‐doped Mo₂C crystals disappears along with the emergence of the Kondo effect, and the Kondo temperature increases monotonously. Using scanning tunneling microscopy/spectroscopy, the mechanism of the doping level effect on the interplay and evolution between superconductivity and the Kondo effect is revealed. This work paves a new way for the synthesis of 2D materials with widely tunable doping levels, and provides new understandings on the interplay between superconductivity and magnetism in the 2D limit.

中文翻译：

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二维Mo2 C超导体中的超高均匀磁性Cr替代，可产生宏观的近藤效应。

替代掺杂为定制2D材料的特性提供了有效的策略，但要实现可调的均匀掺杂（尤其是在高掺杂水平下）仍然是一项公开挑战。这里，2D沫的均匀晶格取代₂由具有受控浓度可达磁性的Cr原子，c超导体≈报道46.9原子％通过化学气相沉积和特别设计的Cu / Cr的/沫三层生长衬底。只需更改Cr层的厚度即可轻松调整Cr原子的浓度，并且样品保留2D Mo ₂的原始结构即使在非常高的Cr浓度下也能达到C。受控的均匀Cr掺杂可在整个样品中调节2D超导体的竞争和近藤效应。迁移测量表明，随着Cr浓度的增加，2D Cr掺杂的Mo ₂ C晶体的超导性随着Kondo效应的出现而消失，并且Kondo温度单调增加。使用扫描隧道显微镜/光谱学，揭示了掺杂水平效应对超导和近藤效应之间相互作用和演化的机理。这项工作为合成具有广泛可调掺杂水平的2D材料开辟了一条新途径，并为2D极限中超导性和磁性之间的相互作用提供了新的认识。