Limpijumnong S, Northrup J E, Van De Walle C G
Xerox Palo Alto Research Center, 3333 Coyote Hill Road, Palo Alto, California 94304.
Phys Rev Lett. 2001 Nov 12;87(20):205505. doi: 10.1103/PhysRevLett.87.205505. Epub 2001 Oct 29.
We present a model for the microscopic structure of Mg-H complexes in GaN, explaining the unusual bond angle observed in recent vibrational spectroscopy studies. The structure is not the lowest-energy configuration at T = 0, but it is stabilized at elevated temperatures due to the large entropy associated with a set of low-energy rotational excitations. The rotational excitation spectrum is calculated using a quantum-mechanical model in which the hydrogen atom moves in a weak corrugation potential. Consequences for experiment are discussed.
我们提出了一种氮化镓中镁 - 氢复合物微观结构的模型，解释了最近振动光谱研究中观察到的异常键角。该结构在T = 0时并非能量最低的构型，但由于与一组低能量旋转激发相关的大熵，它在高温下得以稳定。使用量子力学模型计算旋转激发光谱，其中氢原子在弱起伏势中移动。讨论了该模型对实验的影响。
