Magnetic field induced anomalous Core-Shell magnetic behavior in short-rod Co3O4

Abstract It is found that both spinel structure inversion and the Neel temperature of short-rod Co 3 O 4 are dependent on the applied magnetic field. Spinel structure inversion induced by the applied field results in the change of uncompensated surface spins. Thus, the shell magnetic behavior of short-rod Co 3 O 4 is also field-dependent, which shows ferrimagnetism (FIM) under the low field and antiferromagnetism (AFM) in a high field. This changing shell magnetic behavior leads to anomalous Core-Shell magnetic behavior, that Neel temperature (∼28 K) disappears under the low field and appears again in a high field.