Magnetodielectric effect and spin state of iron ions in iron-substituted bismuth pyrostannate

Lubov Udod, Sergey Aplesnin, Maxim Sitnikov, Oxana Romanova, Oleg Bayukov, Alexander Vorotinov, Dmitriy Velikanov & Gennadiy Patrin. European Physical Journal Plus. https://doi.org/10.1140/epjp/s13360-020-00781-2

The magnetic and magnetodielectric properties of bismuth pyrostannate ${Bi}_{2} ({Sn}_{1 - x} {Fe}_{x})_{2} O_{7}$ ( $x = 0.1$ and 0.2) have been examined. Using the Mössbauer spectroscopy and electron paramagnetic resonance, the high-spin state and crystallographic positions of iron ions have been established. The coexistence of triclinic symmetry domains in the ${Bi}_{2} ({Sn}_{1 - x} {Fe}_{x})_{2} O_{7} (x = 0.1)$ compound with the monoclinic symmetry below 140 K has been found. For the ${Bi}_{2} ({Sn}_{1 - x} {Fe}_{x})_{2} O_{7}$ composition with $x = 0.2$ , the nonlinear field dependence of magnetization in the paramagnetic region up to room temperatures has been observed. The electric polarization hysteresis and the magnetoelectric effect in the ${Bi}_{2} ({Sn}_{1 - x} {Fe}_{x})_{2} O_{7}$ compound have been disclosed. The magnetic field-dependent anomalous behavior of magnetization has been explained by the magnetoelectric effect.