通过CaH₂还原合成块状超导LiNbO₂晶体
Synthesis of Bulk Superconducting LiNbO$_2$ Crystals through CaH$_2$ Reduction
AI总结：
研究通过CaH₂还原LiNbO₃单晶合成超导LiNbO₂晶体，Nb价态降低引发结构转变，经多种表征确定其超导性质及相关参数，证明极端氢化物还原可诱导非拓扑相变，用于合成有奇异性质的块状材料。
AI中文摘要：
我们通过LiNbO₃单晶经CaH₂还原进行体相转变，合成了层状超导LiNbO₂晶体。随着Nb价态从5+降至3+，材料发生结构转变生成LiNbO₂，伴随金属行为和高达14.4K的超导转变起始温度Tc onset。二次离子质谱（SIMS）和X射线光电子能谱（XPS）表明还原过程中通过脱锂使生成相空穴掺杂。隧道二极管谐振器的磁化和交流磁化率测量证实了超导的体性质，超导体积分数约77%，上临界场接近26T。我们的研究表明极端氢化物还原是诱导非拓扑途径相变的有效方法，可用于合成具有奇异性质的块状材料。
英文摘要：
We have synthesized layered superconducting LiNbO$_2$ crystals through a bulk phase transformation from LiNbO$_3$ single crystals via CaH$_2$ reduction. As the Nb valence is reduced from 5+ to 3+, the material undergoes a structural transformation to the resulting product, LiNbO$_2$, which is accompanied by metallic behavior and a superconducting transition, Tc onset, as high as 14.4 K. Secondary ion mass spectroscopy (SIMS) and X-ray photoelectron spectroscopy (XPS) show that the resulting phase is hole-doped through de-lithiation during the reduction. Magnetization and AC susceptibility measurements from a tunnel diode resonator confirm the bulk nature of superconductivity with a superconducting volume fraction of approximately 77% and an upper critical field approaching 26 T. Our study demonstrates extreme hydride reduction as an effective method to induce phase transformations with non-topotactic pathways and can be used to synthesize bulk materials with exotic properties.
