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 BaTiO 3 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 BaTiO 3 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 BaTiO 3 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 BaTiO 3 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 BaTiO 3 powders illustrated the formation of nanosized homogenous particles with less agglomeration. The magnetic field-magnetization loop of pure BaTiO 3 powder shown ferromagnetic order at room temperature. The measured saturation magnetization, retentivity and coercivity of BaTiO 3 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 BaTiO 3 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 BaTiO 3 powder is ten times more than pure BaTiO 3 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.