The Iron Based Superconductors are a class of materials that attracts significant interest both for theoretical studies and practical applications due to their high magnetic critical fields and superconducting critical current densities. In this work, we describe a novel synthesis route to produce the CaKFe₄As₄ compound that consists of a mechanochemical treatment coupled to a mild thermal process. The high energy ball milling step is found to promote the reaction among the pure elements, with the nucleation of a 1144 nanostructured phase observed on the milled compound. The activation of the powders promoted by the mechanochemical step is effective to significantly lower the synthesis temperature with respect to previous literature (T ~ 900 °C), with the 1144 phase obtained in the 500–700 °C temperature range. Furthermore, the effect of an alkaline/alkaline-earth depletion or an iron enrichment on the starting chemical composition is studied: chemical variations are reflected in the formation of secondary phases, without however significantly influencing the superconducting properties of the samples. The superconducting critical current, in particular, seems limited by other extrinsic factors such as porosity and oxygen contamination at the boundaries of dense aggregates produced during the milling step. The reported results suggest that the mechanochemically assisted low temperature method constitutes a promising synthesis route for Ca/K 1144 compounds, highlighting at the same time the need to focus on purification and densification methodologies in view of the development of wires through the powder in tube method.

铁基超导体是一类材料，由于它们的高磁场临界场和超导临界电流密度而在理论研究和实际应用中引起了极大的兴趣。在这项工作中，我们描述了生产CaKFe ₄ As ₄的新颖合成途径由机械化学处理和温和的热处理组成的化合物。发现高能球磨步骤促进纯元素之间的反应，并且在研磨的化合物上观察到1144纳米结构相的成核。相对于先前的文献（T〜900°C），通过机械化学步骤促进的粉末活化有效地降低了合成温度，在500-700°C的温度范围内获得了1144相。此外，还研究了碱性/碱土消耗或铁富集对起始化学成分的影响：化学变化反映在第二相的形成中，但是并未显着影响样品的超导性能。特别是超导临界电流 似乎受到其他外部因素的限制，例如在研磨步骤中产生的致密骨料边界处的孔隙率和氧污染。报道的结果表明，机械化学辅助低温法构成了有前途的Ca / K 1144化合物合成路线，同时强调了鉴于通过管中粉末法开发线材的需求，因此需要专注于纯化和致密化方法学。 。