Abstract Intercalation of alkali metal is an effective way to tune the physicochemical property of polyaromatic hydrocarbons. Herein, we show for the first time that the weak ferromagnetism with a Curie temperature of 5.2 K can be realized in an all-carbon π-electron compound – potassium-intercalated 9-phenylanthracene. The magnetic measurements reveal that there exists an antiferromagnetic transition around 35 K before transition to the weak ferromagnetic phase. An in-depth theoretical investigation indicates that the weak ferromagnetism is produced by the intramolecular ferromagnetic and intermolecular antiferromagnetic spin couplings in the crystal unit cell. Our finding enriches the physical functionality of anthracene derivatives and adds a new member of organic magnetic materials.

中文翻译：

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插钾9-苯基蒽中的π电子弱铁磁性

摘要 碱金属插层是调节多环芳烃理化性质的有效途径。在此，我们首次证明了在全碳 π 电子化合物 - 插钾 9-苯基蒽中可以实现居里温度为 5.2 K 的弱铁磁性。磁性测量表明，在过渡到弱铁磁相之前，在 35 K 附近存在反铁磁过渡。深入的理论研究表明，弱铁磁性是由晶胞中的分子内铁磁和分子间反铁磁自旋耦合产生的。我们的发现丰富了蒽衍生物的物理功能，并增加了有机磁性材料的新成员。