Potassium ions are important for developing electrode materials because they have similar properties to lithium and sodium ions. Mixed chromium phosphates (KMIICr(PO4)2) with substituted MII sites using divalent elements (M = Ni, Co, Cu) were synthesized using a solid-state reaction method. The samples were analyzed using various techniques such as powder X-ray diffraction, Fourier transform infrared, Raman, and electron paramagnetic resonance spectroscopy. The proposed phosphates had a monoclinic phase structure with a P21/n space group, and they contained large tunnels occupied by K+ cations. The dielectric properties showed that the Ni-based phosphates had slower dielectric relaxation, while the Co and Cu-based phosphates had quicker polarization and depolarization processes. Additionally, the resistance of the grains decreased from Ni to Co to Cu-based phosphates, indicating easier charge movement in each material, consistent with the increase in conductive losses and a.c. conductivity when changing the MII ions.

中文翻译：

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过渡金属离子对磷酸铬钾介电性能的影响


钾离子对于开发电极材料很重要，因为它们具有与锂离子和钠离子相似的特性。使用固态反应法合成使用二价元素 （M = Ni， Co， Cu） 的混合磷酸铬 （KMIICr（PO4）2） 和取代的 MII 位点。使用粉末 X 射线衍射、傅里叶变换红外、拉曼和电子顺磁共振光谱等各种技术对样品进行分析。所提出的磷酸盐具有具有 P21/n 空间群的单斜相结构，并且它们包含被 K+ 阳离子占据的大隧道。介电特性表明，Ni 基磷酸盐的介电弛豫较慢，而 Co 和 Cu 基磷酸盐具有较快的极化和去极化过程。此外，晶粒的电阻从 Ni 到 Co 再到 Cu 基磷酸盐降低，表明每种材料中的电荷更容易移动，这与更改 MII 离子时导电损耗和交流电导率的增加一致。