Pressure-stiffened Raman phonons in group III nitrides: a local bond average approach.
Pressure-stiffened Raman phonons in group III nitrides: a local bond average approach.
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DOI：
10.1021/jp711530q
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发表时间：
2008-01
期刊：
影响因子：
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通讯作者：
G. Ouyang;Chang Q. Sun;Weiguang Zhu
中科院分区：
文献类型：
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作者：
G. Ouyang;Chang Q. Sun;Weiguang Zhu
长期以来，关于压力引起的拉曼光学声子硬化的原子起源一直令人困惑，它通常遵循多项式表达式，其系数需要物理指示。在这里，我们证明了键序长度强度相关机制的扩展和压力域的局部键平均方法已经产生了一种解析解，将压力引起的拉曼光学声子硬化直接连接到样本的键合特性以及键合特性对施加的刺激的响应。研究发现，拉曼光学声子的压力引起的蓝移是由压应力施加的键压缩和能量存储引起的。预测和实验测量之间的一致性导致了多项式系数的详细形式的澄清，这提供了对外部压力引起的能量增益、热引起的键膨胀的物理机制的原子理解，以及确定样品中模式原子内聚能的方法。
It has long been puzzling regarding the atomistic origin of the pressure-induced Raman optical phonon stiffening that generally follows a polynomial expression with coefficients needing physical indication. Here, we show that an extension of the bond-order-length-strength correlation mechanism and a local bond average approach to the pressure domain have led to an analytical solution to connect the pressure-induced Raman optical phonon stiffening directly to the bonding identities of the specimen and the response of the bonding identities to the applied stimulus. It is found that the pressure-induced blue-shift of Raman optical phonons arises from the bond compression and energy storage exerted by the compressive stress. Agreement between predictions and experimental measurements lead to the clarification of the detailed form for the polynomial coefficients, which provide an atomistic understanding of the physical mechanism of the external pressure induced energy gain, thermally induced bond expansion, as well as means of determining the mode atomic cohesive energy in a specimen.