Nanostructured antiferromagnetic (AFM) NiO has attracted much attention from both the fundamental and applied perspectives. Understanding the two-magnon (2 M) is of great significance in NiO applications such as spin valves and next-generation magnetic random access memories (MRAM). We investigated the phonon modes and antiferromagnetically ordered states of NiO nanoparticles prepared by empirically controlled measurements. An intensity enhancement of the 2 M mode was observed by Raman spectroscopy as the NiO nanoparticles were vacuum annealed at 650 ℃. The increased 2 M peak intensity in NiO nanoparticles is explained by the local symmetry conversions from NiO₅ to NiO₆ configurations due to the oxygen redistribution during the vacuum annealing. The change of the splitting of anisotropic transverse optical (TO) phonon with different oxygen contents was also revealed by the Raman spectroscopy. We have shown that the changes in the oxygen environment underlie both the change in the 2 M intensity and the splitting of TO phonon in the NiO nanoparticles. Our work offers an efficient avenue to strengthen the AFM ordering and emphasizes the effect of vacuum annealing of the NiO nanoparticles, opening the interesting possibility of individual parameter control in practical applications.

纳米结构反铁磁（AFM）NiO 从基础和应用的角度都引起了广泛关注。了解双磁振子 (2 M) 在自旋阀和下一代磁性随机存取存储器 (MRAM) 等 NiO 应用中具有重要意义。我们研究了通过经验控制测量制备的 NiO 纳米粒子的声子模式和反铁磁有序状态。当 NiO 纳米粒子在 650 ℃ 真空退火时，通过拉曼光谱观察到 2 M 模式的强度增强。_{NiO 纳米粒子中增加的 2 M 峰强度可以通过从 NiO 5}到 NiO ₆的局部对称转换来解释由于真空退火过程中的氧气重新分布而导致的配置。拉曼光谱还揭示了具有不同氧含量的各向异性横向光学 (TO) 声子分裂的变化。我们已经表明，氧气环境的变化是 2 M 强度变化和 NiO 纳米粒子中 TO 声子分裂的基础。我们的工作提供了加强 AFM 排序的有效途径，并强调了 NiO 纳米粒子真空退火的效果，从而在实际应用中开启了单独参数控制的有趣可能性。