We present a new compound in the silver–cobalt-fluoride system, featuring paramagnetic silver (d⁹) and high-spin cobalt (d⁶), synthesized by solid-state method in an autoclave under F₂ overpressure. Based on powder X-ray diffraction, we determined that Ag^IICo^IIIF₅ crystallizes in a monoclinic system with space group C2/c. The calculated fundamental band-gap falls in the visible range of the electromagnetic spectrum, and the compound has the character of charge-transfer insulator. AgCoF₅ is likely a ferrimagnet with one predominant superexchange magnetic interaction constant between mixed spin cations (Ag–Co) of −62 meV (SCAN result). Magnetometric measurements conducted on a powdered sample allowed the identification of a transition at 128 K, which could indicate magnetic ordering.

中文翻译：

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新型三元AgIICoIIIF5氟化物：合成、结构和磁特性

我们提出了一种银-钴-氟化物体系中的新化合物，具有顺磁性银 (d ⁹ ) 和高自旋钴 (d ^{6 )，是在 F} ₂超压下在高压釜中通过固态方法合成的。基于粉末X射线衍射，我们确定Ag ^II Co ^III F ₅结晶为空间群C 2/ c的单斜晶系。计算得到的基本带隙落在电磁波谱的可见光范围内，该化合物具有电荷转移绝缘体的特性。 AgCoF ₅可能是一种亚铁磁体，混合自旋阳离子 (Ag-Co) 之间的主要超交换磁相互作用常数为 -62 meV（扫描结果）。对粉末样品进行的磁力测量可以识别 128 K 的转变，这可以表明磁序。