New perovskite (Y, Zr, Ga)-BaTiO3 nanostructures for spin-memory chips: high intrinsic ferromagnetic order

Ceramic perovskite compounds composed of (Y, Zr) and (Ga, Zr) co-substituted BaTiO3 powders have been synthesized using the solid-state reaction method for applications in spintronics technology. The X-ray diffraction results confirmed that the incorporation of (Y, Zr) and (Ga, Zr) ions into BaTiO3 lattice not changed its tetragonal phase, but affected on the lattice parameters and cell dimension. The study of the optical properties of pure, (Y, Zr) and (Ga, Zr) co-substituted BaTiO3 powders by diffuse reflectance tool demonstrated that these specimens have a band gap energy of 3.26, 3.24 and 3.23 eV, respectively. The TEM morphological image of the pure BaTiO3 powder revealed that the particles are highly agglomerated together in large masses. In contrast, the TEM images of (Y, Zr) and (Ga, Zr) co-substituted BaTiO3 powders illustrated the formation of nanosized homogenous particles with less agglomeration. The magnetic field-magnetization loop of pure BaTiO3 powder shown ferromagnetic order at room temperature. The measured saturation magnetization, retentivity and coercivity of BaTiO3 specimen are 0.08386 emu/g, 71 Oe and 0.00146 emu/g, respectively. The hysteresis loops of non-magnetic (Y, Zr) and (Ga, Zr) codoped BaTiO3 compositions exhibit a complete ferromagnetic order at room temperature with measured saturation magnetization of 0.108 emu/g and 0.812 emu/g, respectively. Interestingly, the saturation magnetization of (Ga, Zr) co-substituted BaTiO3 powder is ten times more than pure BaTiO3 sample (0.08386 → 0.812 emu/g). This research point towards the advanced role of dual-doping on development new compositions appropriate for future electronics based on spin-property.