3d-Electron-doping induced multiferroicity and half-metallicity in PbTiO₃

Abstract

Atomic interactions can be used to control and tune the physical properties of the systems, which are different from the pristine structure. Herein, we explored the ferroelectric, magnetic, and electronic properties of 3d transition metals (TM = Sc, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn)-doped PbTiO3 utilizing density functional theory calculations. The structural stability of the undoped and doped systems is checked by computing the formation enthalpies in terms of the Convex Hull analysis, affirms the experimental realization of all the motifs. It is established that the versatile multiferroic properties can be obtained by TM-doping, which are ranging from non-magnetic/magnetic semiconductor or conductor (Sc-, Zn-, and Ni-doped systems)/(V-, Mn-, Fe-, and Cu-doped systems) to half-metallic ferromagnetic (Cr- and Co-doped systems). The most striking feature of the present study is that Cr- and Co-doped systems display half-metallic behavior along with a moderate spontaneous polarization (SP) of 40.07 and 59.77 μC/cm^−2 , respectively. The metallicity in the spin-minority channel mainly comes from the Cr and Co 3d_yz+xz orbitals with a small contribution from d xy . However, Zn-doped motif displays a higher SP magnitude of 70.32 μC/cm^−2 than that of other doped systems. Finally, the induced magnetism in these doped structures is explained by addressing the low and high spin state configurations of TM ions. As it found that Mn- and Fe-doped structures exhibit a larger moment of 2.9 and 2.7 μ_B and lie in a high spin states of S = 2.0 and 2.02, respectively. Hence, our calculations highly demand the experimental verification of these doped materials for their potential realization in spintronic devices.