CaFe₂O₄ is a highly anisotropic antiferromagnet reported to display two spin arrangements with up–up–down–down (phase A) and up–down–up–down (phase B) configurations. The relative stability of these phases is ruled by the competing ferromagnetic and antiferromagnetic interactions between Fe³⁺ spins arranged in two different environments, but a complete understanding of the magnetic structure of this material does not exist yet. In this study, we investigate epitaxial CaFe₂O₄ thin films grown on TiO₂ (110) substrates by means of pulsed laser deposition (PLD). Structural characterization reveals the coexistence of two out-of-plane crystal orientations and the formation of three in-plane oriented domains. The magnetic properties of the films, investigated macroscopically as well as locally, including highly sensitive Mössbauer spectroscopy, reveal the presence of just one order parameter showing long-range ordering below T = 185 K and the critical nature of the transition. In addition, a non-zero in-plane magnetization is found, consistent with the presence of uncompensated spins at phase or domain boundaries, as proposed for bulk samples.

C a F e ₂ O ₄是一种高度各向异性的反铁磁体，据报道显示两种自旋排列，分别具有上-上-下-下（A相）和上-下-上-下（B相）配置。这些相的相对稳定性由布置在两个不同环境中的F e ³⁺自旋之间竞争性的铁磁和反铁磁相互作用所决定，但是尚不完全了解这种材料的磁结构。在这项研究中，我们研究了在T i O ₂上生长的外延C a F e ₂ O ₄薄膜（110）通过脉冲激光沉积（PLD）的基板。结构表征揭示了两个面外晶体取向的共存和三个面内取向域的形成。薄膜的磁学性质，无论是宏观还是局部研究，包括高度敏感的穆斯堡尔光谱法，都揭示了仅存在一个阶跃参数，表明在T  = 185 K以下具有长程有序性，以及转变的临界性质。此外，发现了一个非零的面内磁化强度，这与在批量样本中提出的在相位或畴边界处未补偿的自旋一致。