GdTe₃ is a layered antiferromagnet which has attracted attention due to its exceptionally high mobility, distinctive unidirectional incommensurate charge density wave (CDW), superconductivity under pressure, and a cascade of magnetic transitions between 7 and 12 K, with as yet unknown order parameters. Here, we use spin-polarized scanning tunneling microscopy to directly image the charge and magnetic orders in GdTe₃. Below 7 K, we find a striped antiferromagnetic phase with twice the periodicity of the Gd lattice and perpendicular to the CDW. As we heat the sample, we discover a spin density wave with the same periodicity as the CDW between 7 and 12 K; the viability of this phase is supported by our Landau free energy model. Our work reveals the order parameters of the magnetic phases in GdTe₃ and shows how the interplay between charge and spin can generate a cascade of magnetic orders.

GdTe ₃ 是一种层状反铁磁体，由于其极高的迁移率、独特的单向不通约电荷密度波 (CDW)、压力下的超导性以及 7 至 12 K 之间的级联磁转变而引起了人们的关注，尚不清楚订单参数。在这里，我们使用自旋偏振扫描隧道显微镜直接对 GdTe ₃ 中的电荷和磁序进行成像。在 7 K 以下，我们发现了条状反铁磁相，其周期性是 Gd 晶格的两倍，并且垂直于 CDW。当我们加热样品时，我们发现自旋密度波在 7 到 12 K 之间具有与 CDW 相同的周期；我们的朗道自由能模型支持了这一阶段的可行性。我们的工作揭示了 GdTe ₃ 中磁相的有序参数，并展示了电荷和自旋之间的相互作用如何产生一系列磁序。