Multifunctional properties of Mn-doped InP: Unveiling ferroelectric, ferromagnetic, and magnetoelectric behaviors

We report the observation of multiferroic behavior in a novel semiconductor-based material system, Mn-substituted InP (InP:Mn) thin films. These films simultaneously exhibit well-defined ferroelectric and ferromagnetic hysteresis loops, with respective Curie temperatures of approximately 470 K and 380 K. First-principles calculations reveal that Mn-V_p defect pairs substitute for In–P pairs, giving rise to local polar defect complexes preferentially aligned along the cubic {111} crystallographic directions. The observed ferroelectricity is attributed to thermally activated hopping of P ions in the vicinity of Mn atoms, resulting in a stable macroscopic polarization. Importantly, the ferroelectric polarization exhibits a measurable dependence on an applied magnetic field, demonstrating robust magnetoelectric coupling in the InP:Mn thin-film system at both cryogenic (3 K) and room temperature (300 K). These coupled ferroic responses are interpreted in terms of a defect-dipole–mediated multiferroic-like behavior arising from the collective alignment and electric-field-driven reorientation of Mn–V_p-related defect dipoles, rather than from a crystallographic phase transition. This defect-dipole–based multiferroicity highlights InP:Mn as a promising platform for multifunctional semiconductor-based spintronic and magnetoelectric applications while providing a physically consistent framework for polar order in a nominally non-polar zinc blende semiconductor.