The novel potassium sulfido cobaltate, K2[Co3S4] is introduced, with 25% vacancies of the cobalt positions within a layered anionic sublattice. The impedance and dielectric investigations indicate a remarkable ionic conductivity of 21.4 mS cm−1 at room temperature, which is in the range of highest ever reported values for potassium‐ions, as well as a high electrical permittivity of 2650 at 1 kHz, respectively. Magnetometry results indicate an antiferromagnetic structure with giant intrinsic exchange bias fields of 0.432 and 0.161 T at 3 and 20 K respectively, potentially induced by a combination of the interfacial effect of combined magnetic anionic and nonmagnetic cationic sublattices, as well as partial spin canting. The stability of the exchange bias behavior is confirmed by a training effect of less than 18% upon 10 hysteresis cycles. The semiconductivity of the material is determined, both experimentally and theoretically, with a bandgap energy of 1.68 eV. The findings render this material as a promising candidate for both, active electrode material in potassium‐ion batteries, and for spintronic applications.

中文翻译：

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深入了解有缺陷的硫化钴酸钾：巨大的磁交换偏压、离子电导率和介电常数


引入了新型硫化钴酸钾 K2[Co3S4]，其层状阴离子亚晶格内的钴位置有 25% 的空位。阻抗和介电研究表明，室温下离子电导率高达 21.4 mS cm−1，这是钾离子有史以来报道的最高值范围，并且在 1 kHz 时介电常数分别为 2650。磁力测量结果表明，反铁磁结构在 3 和 20 K 下分别具有 0.432 和 0.161 T 的巨大本征交换偏置场，这可能是由磁性阴离子和非磁性阳离子亚晶格组合的界面效应以及部分自旋倾斜的组合引起的。 10 个滞后周期后训练效果低于 18%，证实了交换偏差行为的稳定性。该材料的半导率通过实验和理论测定，带隙能为 1.68 eV。这些发现使得这种材料成为钾离子电池活性电极材料和自旋电子应用的有前途的候选材料。