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

Abstract

The magnetic and magnetodielectric properties of bismuth pyrostannate $$\hbox {Bi}_{{2}}(\hbox {Sn}_{1-{x}}\hbox {Fe}_{{x}})_{{2}}\hbox {O}_{{7}}$$ ( $$x = 0.1$$ and 0.2) have been examined. Using the Mossbauer 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 $$\hbox {Bi}_{{2}}(\hbox {Sn}_{{1-{x}}}\hbox {Fe}_{{x}})_{{2}}\hbox {O}_{{7}}(x = 0.1)$$ compound with the monoclinic symmetry below 140 K has been found. For the $$\hbox {Bi}_{{2}}(\hbox {Sn}_{{1-{x}}}\hbox {Fe}_{{x}})_{{2}}\hbox {O}_{{7}}$$ 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 $$\hbox {Bi}_{{2}}(\hbox {Sn}_{{1-{x}}}\hbox {Fe}_{{x}})_{{2}}\hbox {O}_{{7}}$$ compound have been disclosed. The magnetic field-dependent anomalous behavior of magnetization has been explained by the magnetoelectric effect.