First Principle Study of Structural, Electronic and Magnetic Properties of Doped TbMnO3 for Transportation in Spintronic Devices

Abstract

Multiferroic Terbium Magnate, TbMnO3 (TMO), is one of the most investigated compounds for advances in spintronic devices. Single-phase multiferroic TMO can play an important role in the development of spintronics random access memory (RAM) due to its spin-polarized electronic, magnetic, and dielectric properties. However, the major challenge in the field of spintronic RAM technology is to generate a balanced magnetization of 25 MA/cm, more than 80% spin polarization at the Fermi level, and suitable dielectric constant in the range of 10 to 52. The present research work explores the structural, spin-polarized electronic, dielectric, and magnetic properties of Dysprosium (Dy) doped TMO structure for spintronic memory device application using first-principles calculations. The generalized gradient approximation (GGA) with Perdew-Burke Ernzerhof (PBE) is used to perform numerical simulation using CASTEP numerical coding. Dy impurities in TMO structure change the lattice constant, volume, and bond length, which profoundly affects the material's properties. The band gap in the spin-up and spin-down states is altered by the inclusion of Dy atoms due to increase in the energy states. The additional energy levels significantly enhance the spin polarization at the Fermi level, which is more favorable for spintronic devices. The addition of Dy-dopants as mono, di and triatomic in Pure TMO 2x2x2 super cell results in decrease in the magnetic moment. The half metallicity or 86.3 % spin polarization at the Fermi level, high dielectric constant of 1520.65, appropriate magnetism of 34.69 MA/cm has been observed for triatomic Dy doped TMO material in orthorhombic phase. Thus, triatomic Dy-doped TMO is a potential single-phase material spintronic ferro memory device applications.