Investigation of new magnetoelastic and magnetic transitions accompanied with magnetoelectric coupling in [Formula: see text] multiferroic

A new multiferroic solid solution [Formula: see text] has been developed and characterized for structure, phase transition, magnetoelectric and magnetoelastic coupling. Temperature dependent measurement of dc-magnetization [Formula: see text] on [Formula: see text] ceramic shows two magnetic transitions one around [Formula: see text]42 K and the second at [Formula: see text]130 K. The real part of dielectric permittivity exhibits step like change at the magnetic anomaly temperature ([Formula: see text]130 K) which indicates the presence of magnetoelectric coupling. The change in the value of dielectric permittivity on the application of magnetic field confirms the presence of magnetoelectric coupling in [Formula: see text] ceramic. The room temperature polarization (P)-electric field (E) hysteresis loop measurement shows week ferroelectric nature of sample while the magnetization (M) versus magnetic field (H) measurement suggest weakly ferromagnetic character. The ferroelectric nature of sample was further confirmed by calculating remanent polarization using PUND measurement. The Rietveld structural analysis of low temperature x-ray powder diffraction data does not reveal any crystallographic phase transition in terms of peak splitting or new reflections. However, temperature dependence of lattice parameters, tetragonality, unit cell volume, [Formula: see text] octahedral tilt angle ([Formula: see text]), [Formula: see text] bond length and [Formula: see text] bond angles reveal discontinuous changes at both the magnetic transitions observed in temperature dependence of magnetization. This confirms that both the magnetic anomalies (around [Formula: see text]42 K and [Formula: see text]130 K) exhibit magnetoelastic coupling accompanied with isostructural transitions.