一个材料学家对室温超导材料LK-99的看法
对于LK-99，学术共同体应该秉承科学的态度，更加包容地对待新发现。关于目前对LK-99是否室温超导体的争议，做为一个还算专业的材料学家（非超导专家），以下三点请大家关注：
1）既然我们认为室温超导理论应该是一个全新的理论。BCS理论仅能解释低温超导，而高温超导理论尚不完善。为什么我们仍要用“传统”的超导理论来评价室温超导材料呢？
2）由LK-99的结构示意图可知（图1a），LK-99是一种层状材料，其超导相是跨层形成的一维超导链。可以看出，这种低维的超导是有取向性的。那么，在用四点法测试电阻时，似乎应该按图1b的方式沿Z轴进行引线才能获得准确的结果，而目前的实验因为材料厚度不够，都是按图1c的方式在X-Y面内进行引线测试的，势必会极大地影响检测结果。
3）在某些“迈斯纳”效应测试实验中，已经表明了LK-99的“磁场钉扎”效应，而不是普通的抗磁性。我们更应该相信之所以LK-99尚未展现出完美的所谓的“迈斯纳”效应，只是由于材料制备方法不完善而导致的样品质量问题（如缺陷、超导相的连续性和分布密度等）。
总之，虽然现有结果尚不能证明LK-99就是一种”传统”意义上室温超导材料，但其独特的性能已经在预示着一种新材料和新结构的诞生。我们应该结合现有实验结果，不断完善材料制备方法，并对其进行详细的结构和基本物性表征，在此基础上建立新理论，并指导新材料的设计。
A Materials Scientist's Perspective on the Room-Temperature Superconducting Material LK-99
Regarding LK-99, the academic community should adopt a scientific attitude and be more tolerant towards new discoveries. As for the current controversy over whether LK-99 is a room-temperature superconductor, as a somewhat professional materials scientist (not a superconductor expert), I ask everyone to pay attention to the following three points:
1) Since we believe that the theory of room-temperature superconductivity should be a completely new theory. The BCS theory can only explain low-temperature superconductivity, while the theory of high-temperature superconductivity is still imperfect. Why do we still want to evaluate room-temperature superconducting materials with the "traditional" superconductivity theory?
2) As can be seen from the structural diagram of LK-99 (Figure 1a), LK-99 is a layered material, and its superconducting phase is a one-dimensional superconducting chain formed across layers. It can be seen that this kind of low-dimensional superconductivity has directionality. Therefore, when testing resistance with the four-point method, it seems that leads should be made along the Z-axis as shown in Figure 1b to obtain accurate results, while current experiments are conducting leads in the X-Y plane as shown in Figure 1c due to insufficient material thickness, which will inevitably greatly affect the detection results.
3) In some "Meissner" effect test experiments, the pinning effect of LK-99 has been demonstrated, rather than ordinary diamagnetism. We should be more inclined to believe that the reason why LK-99 has not yet shown the perfect so-called "Meissner" effect is just due to the imperfections in the material preparation method leading to sample quality issues (such as defects, continuity of the superconducting phase, and distribution density, etc.).
In conclusion, although the existing results cannot prove that LK-99 is a "traditional" room-temperature superconducting material, its unique properties are already indicating the birth of a new material and structure. We should combine the existing experimental results, continuously improve the material preparation methods, carry out detailed structural and basic physical property characterizations, establish new theories on this basis, and guide the design of new materials.
