基于高压技术的高温超导体制备及研究进展

Preparation and Research Progress of High-Temperature Superconductors Based on High Pressure Technique

摘要:

在超导材料研究领域，从金属汞单质超导体的发现到镍基超导体的制备，对超导材料物理性质和微观机理的研究极大推动了凝聚态物理学的发展。基于新制备技术研发实用化高温超导体，在强电和弱电应用领域具有重要的意义。高压实验技术作为一种新手段，已成为探索新奇超导体及提高超导体超导转变温度（T_c）的强力工具之一。本文以超导转变温度较高（大于150 K）的3种高温超导体H₃S、LaH₁₀和HgBaCaCuO为对象，系统地总结了其制备技术的研究进展，明确实用化高温超导体的制备思路。通过分析得出以下主要结论，高压有助于制备具有特殊晶体结构的富氢化合物超导体LaH₁₀，使其获得较高的超导转变温度；同时，高压也能够以类似改变掺杂的方式影响铜氧化物超导体，从而改变其超导电性。高压技术是获得具有特殊晶体结构（层状和笼状）高温超导体的有效途径。

Abstract:

In the field of superconducting materials research, from the discovery of elemental mercury as a superconductor to the preparation of nickel-based superconductors, the study on physical properties and microscopic mechanisms of superconducting materials has greatly promoted the development of condensed matter physics. The development of practical high-temperature superconductors based on new preparation techniques plays an extremely important role in the fields of strong and weak electricity. As a new means, the high-pressure experimental technique has become one of the powerful tools for exploring novel superconductors and increasing their superconducting transition temperature (T_c). Focusing on three high-temperature superconductors with relatively high superconducting transition temperatures (exceeding 150 K), including H₃S, LaH₁₀ and HgBaCaCuO, this paper summarizes the research progress in their preparation techniques and clarifies the preparation strategies of practical high-temperature superconductors. It is concluded that high pressure facilitates the preparation of LaH₁₀, a hydrogen-rich compound superconductor with a special crystal structure, so that it can obtain a higher superconducting transition temperature. At the same time, high pressure can also affect copper oxide superconductors in a similar way of changing doping, thereby changing their superconductivity. High pressure technique is an effective way to fabricate high-temperature superconductors with special crystal structures (layered and caged).