While 3d-containing materials display strong electron correlations, narrow band widths, and robust magnetism, 5d systems are recognized for strong spin–orbit coupling, increased hybridization, and more diffuse orbitals. Combining these properties leads to novel behavior. Sr₃NiIrO₆, for example, displays complex magnetism and ultra-high coercive fields—up to an incredible 55 T. Here, we combine infrared and optical spectroscopies with high-field magnetization and first-principles calculations to explore the fundamental excitations of the lattice and related coupling processes including spin–lattice and electron–phonon mechanisms. Magneto-infrared spectroscopy reveals spin–lattice coupling of three phonons that modulate the Ir environment to reduce the energy required to modify the spin arrangement. While these modes primarily affect exchange within the chains, analysis also uncovers important inter-chain motion. This provides a mechanism by which inter-chain interactions can occur in the developing model for ultra-high coercivity. At the same time, analysis of the on-site Ir⁴⁺ excitations reveals vibronic coupling and extremely large crystal field parameters that lead to a t_2g-derived low-spin state for Ir. These findings highlight the spin–charge–lattice entanglement in Sr₃NiIrO₆ and suggest that similar interactions may take place in other 3d/5d hybrids.

含3 d的材料显示出很强的电子相关性，窄的带宽和强大的磁性，而公认的5 d系统具有强的自旋-轨道耦合，增加的杂交和更多的扩散轨道。结合这些特性会导致新颖的行为。Sr ₃ NiIrO ₆例如，显示复杂的磁场和高达500 T的超高矫顽力。在这里，我们将红外光谱和光学光谱与高场磁化强度和第一性原理计算相结合，以探索晶格的基本激发及​​相关耦合过程包括自旋-晶格和电子-声子机理。磁红外光谱揭示了三个声子的自旋-晶格耦合，这些声子调节Ir环境，从而降低了改变自旋排列所需的能量。尽管这些模式主要影响链内的交换，但分析还揭示了重要的链间运动。这提供了一种机制，通过该机制可以在开发模型中发生链间相互作用以实现超高矫顽力。同时，对现场Ir ^4+的分析激发揭示了振动耦合和极大的晶体场参数，这些参数导致Ir的t _{2 g}衍生的低自旋态。这些发现突出了Sr ₃ NiIrO _6中的自旋-电荷-晶格缠结，并表明在其他3 d / 5 d杂种中可能发生类似的相互作用。