Hexagonal LuFe₂O₄ is a promising charge order (CO) driven multiferroic material with high charge and spin-ordering temperatures. The coexisting charge and spin orders on Fe³⁺/Fe²⁺ sites result in magnetoelectric behaviors, but the coupling mechanism between the charge and spin orders remains elusive. Here, by tuning external pressure, we reveal three charge-ordered phases with suggested correlation to magnetic orders in LuFe₂O₄: (i) a centrosymmetric incommensurate three-dimensional CO with ferrimagnetism, (ii) a non-centrosymmetric incommensurate quasi-two-dimensional CO with ferrimagnetism, and (iii) a centrosymmetric commensurate CO with antiferromagnetism. Experimental in situ single-crystal X-ray diffraction and X-ray magnetic circular dichroism measurements combined with density functional theory calculations suggest that the charge density redistribution caused by pressure-induced compression in the frustrated double-layer [Fe₂O₄] cluster is responsible for the correlated spin-charge phase transitions. The pressure-enhanced effective Coulomb interactions among Fe-Fe bonds drive the frustrated (1/3, 1/3) CO to a less frustrated (1/4, 1/4) CO, which induces the ferrimagnetic to antiferromagnetic transition. Our results not only elucidate the coupling mechanism among charge, spin, and lattice degrees of freedom in LuFe₂O₄, but also provide a new way to tune the spin-charge orders in a highly controlled manner.

六方 LuFe ₂ O ₄是一种很有前景的电荷有序 (CO) 驱动的多铁材料，具有高电荷和自旋有序温度。^{Fe 3+} /Fe ²⁺位置上共存的电荷和自旋序导致磁电行为，但电荷和自旋序之间的耦合机制仍然难以捉摸。在这里，通过调节外部压力，我们揭示了三个电荷有序相，这些相与 LuFe ₂ O _{4中的磁序具有建议的相关性}：（i）具有亚铁磁性的中心对称不相称三维 CO，（ii）具有亚铁磁性的非中心对称不相称准二维 CO，以及（iii）具有反铁磁性的中心对称相称 CO。实验原位单晶 X 射线衍射和 X 射线磁圆二色性测量结合密度泛函理论计算表明，受抑双层 [Fe ₂ O _{4中压力诱导压缩引起的电荷密度重新分布}]簇负责相关的自旋电荷相变。Fe-Fe 键之间压力增强的有效库仑相互作用将受抑的 (1/3, 1/3) CO 驱动为受抑较小的 (1/4, 1/4) CO，从而诱导亚铁磁向反铁磁转变。_{我们的结果不仅阐明了 LuFe 2} O ₄中电荷、自旋和晶格自由度之间的耦合机制，而且提供了一种以高度可控的方式调整自旋电荷级数的新方法。