Magnetic properties of R2Fe3O7 (R=Yb and Lu)

•Higher Néel temperature of R2Fe3O7 than that of the related multiferroic RFe2O4.•Magnetic features governed by ferromagnetic–antiferromagnetic competition.•Magnetic entropy change at around room temperature suitable for application.

We have investigated the magnetic properties of R2Fe3O7 (R=Yb and Lu), which belongs to the homologous family of electronic ferroelectric RFe2O4. Magnetization measurements show ferrimagnetic ordering at the Néel temperature (TN) of ~270 K, which is slightly higher than that of RFe2O4 (TN~230–250 K). Observation of spin glass and exchange bias shows a coexistence of ferromagnetic and antiferromagnetic interactions, similarly to RFe2O4. This situation gives rise to a complex magnetic change and a broad peak of magnetic entropy change. Some characteristics, such as refrigeration temperatures higher than in RFe2O4, seem to offer a possibility of this system to applications.