过渡金属轻元素化合物的高温高压制备

过渡金属轻元素化合物（TMLEs）由于具备高硬度，高熔点，优异电学、磁学、超导等性质受到广泛关注，是一类 具有优异力学性能的功能性材料。优异力学性能与功能性的结合使TMLEs成为极端环境下使用的特种材料。然而， TMLEs的制备往往需要高温高压（HPHT）极端实验条件来克服能垒。目前，已经有了大量HPHT制备TMLEs的报道， 然而，多数只关注产物的性质，对在HPHT下TMLEs的生长机制报道较少。因此，总结HPHT制备的TMLEs，分析TMLEs的晶体生长过程，对理解TMLEs的晶体生长机理、探究新型 TMLEs的制备具有重要意义。结合本课题组研究 经验及其他相关文献，总结了HPHT方法制备的过渡金属硼化物（TMBs）、碳化物（TMCs）和氮化物（TMNs）的晶体生 长情况，分别从起始原料、温压条件、晶体形貌等方面分析了TMLEs的生长机制。总结如下：通过原料配比和温度控 制是制备TMBs单一相的关键，提出硼亚结构单元是使TMBs形成台阶式生长模式的本质因素，碳源和氮源的选择决 定了 TMCs和TMNs的生长机制。同时提出，缺少利用HPHT制备TMLEs毫米级单晶的报道，限制了TMLEs部分本 征的性质探究；并且，新型高轻元素含量的TMLEs结构依然有待开发。随着人类对材料的要求越来越苛刻，以及TMLEs的不断发展，TMLEs将在未来特种材料领域具有不可替代的地位。

Transition Metal Light Elements Compounds Synthesized by High Pressure and High Temperature

Transition metal light elements compounds (TMLEs) are a kind of robust functional materials due to high hardness, high melting point, superior conductivity, magnetic properties, and superconductivity. The combination of excellent mechanical properties and functionality makes TMLEs special materials used in extreme environments. However, synthesizing TMLEs need high pressure and high temperature (HPHT) conditions to overcome the energy barrier. Although many TMLEs were synthesized by HPHT, the growth mechanism is still mysterious. Summary of TMLEs synthesized by HPHT is significant to understand the growth process and develop of new TMLEs. In this work, the TMLEs synthesized by HPHT which include our groups research experience and other relevant literatures are summarized. The TMLEs include transition metal borides (TMBs), transition metal carbides (TMCs), and transition metal nitrides (TMNs). The starting materials, experimental conditions, and morphologies etc. are analyzed. The main results are as follows: proportion of starting materials and the suitable temperature are very important to obtain the single phase of TMBs; the boron subunit in TMBs is related to growth kinetics, which induces step growth process; choosing different starting materials of carbon and nitrogen will define the growth process of TMLEs. Synthesizing single crystal with millimeter size in the future is meaningful to understand the basic properties of TMLEs. The new structures of TMLEs with high content of light elements still need to be developed. With the development of new materials, TMLEs will be a kind of irreplaceable robust materials in the future.