发表机构
Materials Science and Technology Division, Oak Ridge National Laboratory; Faculty of Applied Physics and Mathematics and Advanced Materials Centre, Gdansk University of Technology（橡树岭国家实验室; 格但斯克理工大学应用物理与数学学院及先进材料中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究合成了首批Ir基$Ln_2M$Al$_4$Ge$_2$化合物Tb$_2$IrAl$_4$Ge$_2$和Er$_2$IrAl$_4$Ge$_2$，发现其具有易轴磁各向异性，前者在25K以下反铁磁有序并出现场致变磁跃迁，后者则展现出更丰富的低温磁相图，拓展了该家族的化学空间。
AI 中文摘要
我们报道了单晶 Tb$_2$IrAl$_4$Ge$_2$ 和 Er$_2$IrAl$_4$Ge$_2$ 的合成与全面研究，它们是 $Ln_2M$Al$_4$Ge$_2$ 家族中首批含 Ir 的成员。两种化合物均结晶为四方 Tb$_2$NiAl$_4$Ge$_2$ 型结构（空间群 $I4/mmm$），并表现出易轴磁各向异性，其中晶格 $c$ 轴为优先磁化方向。Tb$_2$IrAl$_4$Ge$_2$ 在 $T_N = 25$ K 以下发生反铁磁有序，并发展出一系列场致变磁跃迁，伴随显著的磁输运异常，包括非线性霍尔响应。相比之下，Er$_2$IrAl$_4$Ge$_2$ 表现出三次连续的零场磁转变，以及一个更为丰富的低温磁相图，包含多个相互竞争的场致相，且这些相局限于相对较小的磁场中。Tb 基与 Er 基化合物之间的差异展示了在 \ce{Tb2NiAl4Ge2} 型结构内可实现广泛的磁行为。更广泛地说，Ir 基 $Ln_2M$Al$_4$Ge$_2$ 化合物的成功实现极大地扩展了该家族的可用化学空间，并为探索相关的 $4d$ 和 $5d$ 基铝锗化物开辟了途径。
英文摘要
We report the synthesis and comprehensive investigation of single-crystalline Tb$_2$IrAl$_4$Ge$_2$ and Er$_2$IrAl$_4$Ge$_2$, the first Ir-based members of the $Ln_2M$Al$_4$Ge$_2$ family. Both compounds crystallize in the tetragonal Tb$_2$NiAl$_4$Ge$_2$-type structure (space group $I4/mmm$) and exhibit easy-axis magnetic anisotropy with the crystallographic $c$ axis as the preferred magnetization direction. Tb$_2$IrAl$_4$Ge$_2$ undergoes antiferromagnetic ordering below $T_N = 25$ K and develops a sequence of field-induced metamagnetic transitions accompanied by pronounced magnetotransport anomalies, including a nonlinear Hall response. In contrast, Er$_2$IrAl$_4$Ge$_2$ exhibits three successive zero-field magnetic transitions and a substantially richer low-temperature magnetic phase diagram comprising multiple competing field-induced phases confined to relatively modest magnetic fields. The differences between the Tb- and Er-based compounds demonstrate the wide range of magnetic behavior that can be realized within the \ce{Tb2NiAl4Ge2}-type structure. More broadly, the successful realization of Ir-based $Ln_2M$Al$_4$Ge$_2$ compounds considerably expands the accessible chemical space of this family and opens a route toward the exploration of related $4d$- and $5d$-based aluminogermanides.
Journal refPhys. Rev. Materials 10, 104401 (2026)
