The 6H-perovskites Ba₃(R/M)Ru₂O₉ (R = rare Earth, M = transition metal) exhibit complex magnetism and have been extensively studied recently for their magnetodielectric (MD) properties. Here, we present a detailed study of structural, magnetic, thermodynamic and MD properties of a 6H-perovskite Ba₃DyRu₂O₉. This compound is found to undergo long range antiferromagnetic ordering below ∼5.8K (T _N), along with the presence of metamagnetic transition at low temperatures. The heat capacity shows two additional anomalies at ∼28K (T ₁) and ∼33K (T ₂), besides the anomaly at T _N. Signature of these anomalies is also visible in the derivative of magnetization curve. The dielectric response also shows weak anomalies around T ₁ and T ₂ at zero field whereas anomaly at T ₂ gets suppressed at 80 kOe. The observed MD coupling of ∼2%–4% at 80 kOe field below ∼30K temperature range, is among the highest values observed for the compounds of this family. Low temperature crystal structures of the compound show sharp distortion of Ru₂O₉ octahedra near T ₂. Our study points toward the emergence of structurally driven spin correlations of Ru moments resulting in the observed MD coupling in this compound.

6H-钙钛矿 Ba ₃ (R/M)Ru ₂ O ₉ ( R = 稀土，M = 过渡金属) 表现出复杂的磁性，最近因其磁介电 (MD) 特性而被广泛研究。在这里，我们详细研究了6H-钙钛矿 Ba ₃ DyRu ₂ O ₉的结构、磁性、热力学和 MD 特性。发现该化合物在低于~5.8K ( T _N ) 时经历长程反铁磁排序，同时在低温下存在变磁转变。热容量显示出两个额外的异常，分别位于 ~28K ( T ₁ ) 和 ~33K ( T ₂ )，除了T _N处的异常。这些异常的特征在磁化曲线的导数中也可见。的介电响应还示出了围绕弱异常Ť ₁和Ť ₂在零电场而异常在Ť ₂在80千奥斯特得到抑制。在低于约 30K 温度范围的 80 kOe 场下观察到的 MD 耦合约为 2%–4%，是该家族化合物观察到的最高值之​​一。该化合物的低温晶体结构在T ₂附近显示出Ru ₂ O ₉八面体的急剧畸变 . 我们的研究指出了 Ru 矩的结构驱动自旋相关性的出现，导致在该化合物中观察到 MD 耦合。