X. Obradors,  T. Puig,*  M. Gibert,  A. Queraltó,  J. Zabaleta and  N. Mestres Chem. Soc. Rev., 2014,43, 2200-2225

M. Coll, J. J. Montero, J. Gazquez, K. Nielsch, X. Obradors and T. Puig Advanced Functional Materials, 24, 5368-5374 (2014) DOI: 10.1002/adfm.201400517 In this work heteroepitaxial stabilization with nanoscale control of the magnetic Co₂FeO₄phase at 250 °C is reported. Ultrasmooth and pure Co₂FeO₄ thin films (5–25 nm) with no phase segregation are obtained on perovskite SrTiO₃ single crystal (100) and (110) oriented substrates by atomic layer deposition (ALD). High resolution structural and chemical analyses confirm the formation of the Co-rich spinel metastable phase. The magneto-crystalline anisotropy of the Co₂FeO₄ phase is not modified by stress anisotropy because the films are fully relaxed. Additionally, high coervice fields, 15 kOe, and high saturation of magnetization, 3.3 μ_B per formula unit (at 10 K), are preserved down to 10 nm. Therefore, the properties of the ALD-Co₂FeO₄ films offer many possibilities for future applications in sensors, actuators, microelectronics, and spintronics. In addition, these results are promising for the use of ALD compared to the existing thin-film deposition techniques to stabilize epitaxial multicomponent materials with nanoscale control on a wide variety of substrates for which the processing temperature is a major drawback.