Fundamental Research on Nitride Metalirgy-New Rovte for GaN Synthesis-

GaN是一种重要的功能材料，因为它能够发射短波长的光。虽然在中等温度下通过氮气氮化镓金属在化学上是可行的，但在常压下实际上是困难的，因为初始反应导致GaN层，其形成对进一步反应的有效屏障。在这篇文章中，我们证明了一种复合氮化物，如Li_3GaN_2，可以在镓合金的氮气氮化过程中作为反应介质。GaN的合成没有镓和氮气之间的直接物理接触。通过测量Li_3GaN_2的热力学性质证实了该反应的可行性，并利用由本研究结果建立的等温化学势图讨论了该反应的机理。以Li_3GaN_2为例，用原电池法测定了Li_3GaN_2的生成吉布斯自由能，讨论了GaN/Li_3GaN_2两相平衡时氮的化学势范围。证明了通过介体分析GaN合成的可行性的新方法。

GaN is an important functional material because of its ability to emit short wave length light. Although nitriding of gallium metal by nitrogen gas is thermodynamically feasible at moderate temperatures, it is practically difficult under a normal pressure because incipient reaction leads to a layer of GaN which forms an effective barrier to further reaction. In this communication, we show that a complex nitride such as Li_3GaN_2 can act as a reaction mediator during nitriding of gallium alloys with nitrogen gas. GaN is synthesized without direct physical contact between gallium and nitrogen gas. Feasibility of this reaction is confirmed by measuring thermodynamic properties of Li_3GaN_2, and mechanism of this reaction is discussed using an isothermal chemical potential diagram constructed from the results of the present study. For example, the Gibbs energy of formation of Li_3GaN_2 is determined by measuring electromive force measurement using galvanic cell, and potential range of nitrogen chemical potential under GaN I Li_3GaN_2 two phase equilibrium is discussed. New approach for analyzing the feasibility of GaN synthesis through a mediator is demonstrated.