Effect of dynamic sintering conditions on the room-temperature magnetoelectric response of multiferroic Sr3Co2Fe24O41

The effects of dynamic oxygen gas pressure during sintering on the room-temperature magnetoelectric effect (ME) of multiferroic Z-type hexaferrite Sr3Co2Fe24O41 were investigated for the first time. A maximum electrical resistivity of 2.78x10(9) Omega cm was obtained for samples sintered in a dynamic oxygen gas flow of 0.3 L/min. An important finding was that under high dynamic oxygen gas pressure during sintering a significantly broadening of the magnetic field range in which the ferroelectric phase state occurs was achieved. That is, the stability of the transverse conical spin structure is greatly enhanced by a high sintering oxygen gas pressure. Furthermore, the high sintering oxygen gas flow effectively decreases the leakage current and trapped states related to oxygen vacancies, stabilizing the ME and providing a more robust and unambiguous measurement of the magnetoelectric effect. (c) 2020 Published by Elsevier B.V.