Bi-substitution-induced magnetic moment distribution in spinel BixCo2&#8722

Abstract

We report the near-edge x-ray absorption spectroscopy (NEXAFS) at the Co/Mn L3,2 edge and oxygen K edge of the well-characterized Bi-substituted Co2MnO4 multiferroic samples. The evolution of peak features in NEXAFS spectra of the Co/Mn L3,2 edge and O K edge show the Bi-induced redistribution of magnetic cations (Co/Mn). The variation in valence states of Co and Mn in all the substituted compositions is consistent with the observed ferrimagnetic behaviour of the samples. Magnetization data show the decrease in molecular field complementing the ferrimagnetism. The role of Bi in the enhancement of magnetic interactions as well as the appearance of ferroelectricity in BixCo2−xMnO4 (0 ≤ x ≤ 0.3) is discussed.