Influence of Ni and Co doping on the stability of the ErMnO3 perovskites processed by mechanochemical synthesis

Mechanosynthesis in tungsten carbide vessels and planetary mill is an effective method to prepare materials with ErMnO3 derived compositions and perovskite-type structure. In this work, the effect of the doping with low contents of Co and Ni cations on the stability of such oxides is studied. The obtained perovskites are highly distorted for all compositions. The transition to the more stable hexagonal phase occurs at lower temperatures for Co-doped materials, due to the presence of Co3+ cations that do not involve any change of oxidation state for Mn3+ Jahn–Teller cations. Spark Plasma Sintering (SPS) was carried out at 900 °C or 950 °C and 120 MPa to obtain dense ceramics, keeping the perovskite-type structures. The magnetic properties of the obtained materials are also shown.