Exploring the effect of Bi doping in cubic spinel BixCo2-xMnO4 by employing neutron diffraction

The effect of Bi doping is studied in cubic spinel Bi_xCo_2-xMnO₄ on their crystal as well as magnetic structure by employing neutron diffraction. Doping of nonmagnetic Bi ion at Co site make this compound more susceptible for ferroelectric properties, which have previously been established by employing XRD, magnetization, magnetodielectric, XMCD and other characterization techniques. Since neutron diffraction is a technique which can look in to microscopic aspects of crystal and magnetic structure more precisely, these series of samples are characterized by employing neutron diffraction. The room temperature neutron diffraction reveals that samples are formed in the cubic spinel structure with Fd3m (s.g. no. = 227). Magnetic structure of title compound of Co₂MnO₄ is scarcely studied. In order to understand the implication on the spin structure and magnetism, temperature dependent neutron diffraction study is carried out on some of the samples in the series. Earlier reported experimental finding upon Bi-doping, such as variation in the ferroelectric properties modification in magnetic properties etc. are discussed and understood in terms of variation in bond lengths and their effect on the CoO₆ polyhedra.