First-Principles Study on Polymorphs of AgVO3: Assessing to Structural Stabilities and Pressure-Induced Transitions
In this paper, we present a comprehensive theoretical study, based on density-functional theory calculations, and which focuses on the structural and electronic properties of silver vanadium oxide (AgVO3) in the monoclinic [Cm (β-AgVO3), C2/c (α-AgVO3), and Cc], orthorhombic (Amm2), and cubic (Pm3̅m) phases from 0–30 GPa. The structural and electronic properties, the stability of different phases, and the pressure-induced solid–solid phase transitions of AgVO3 have been previously studied. The effects of pressure on the band structures, energy–gap values, density of states, and vibrational frequencies are also studied. Numerical and analytical calculations are conducted to obtain the lattic…
Theoretical approach for determining the relation between the morphology and surface magnetism of Co3O4
Abstract Precisely controlling the different aspects of the morphology and magnetic properties of metal oxides are fundamental to materials design. A theoretical approach, based on the Wulff construction and magnetization density (M) index, is presented to clarify the relation between the morphology and surface magnetism. The M index allows us to evaluate the uncompensated spins at the (1 0 0), (1 1 0), (1 1 1) and (1 1 2) surfaces of Co3O4 with a spinel structure. The investigated morphologies show an excellent agreement with the experimental results, with the main contribution coming from the (1 0 0) and (1 1 1) magnetic planes. The present results are also helpful in clarifying the intri…