Lead phosphate glass Nd-doped by first principles calculations

Abstract

Using first-principles calculations based on density functional theory (DFT), the atomic and electronic properties of the amorphous Pb3(PO4)2 and Pb2(PO4)2:Nd3+ were studied, treating these materials as crystals in a short-range order. The calculation of state density, energy bands and charge density showed the absence of a band gap in the Nd-doped structure, indicating the predominance of the covalent character of the PbPO bond concerning the ionic character of Nd2O3. As Nd3+ attracts units that present [PO4] to compensate the charges and produce competition between these cations, the presence of impurity Nd3+ does not distort the atomic structure of Pb3(PO4)2 in the immediate neighborhood of this defect. Structures with zero or very narrow gaps have applications in spintronics, electronics, optical sensors and topological insulators.