Ferroelectric Properties of KNbO3 Doped with Na : First-Principles Calculations

Abstract

The traditional BaTiO3/PbTiO3 ferroelectric material has excellent performance and is widely used, but the Pb in the material has polluted the environment. Studies have found that other ferroelectric materials can also have good performance after doping and improvement. The problem is that the development is too slow. If a reasonable explanation can be given for the changes from the original structure, the research and development process will be accelerated. In this paper, we investigated the ferroelectric properties at the orthogonal-crystal KNbO3 using first-principles calculations coupled with a phenomenological theory model. By replacing the K atoms with Na, studying the stability, polarization, energy band, and density of states after replacement doping, explaining the internal mechanism of its generation, and providing theoretical support for the research and development of new materials.

Doping Effects on the Multiferroic Properties of KNbO3 Nanoparticles

“…The results are demonstrated in Figure 2, curve 3. A similar increase in the electric properties in Na-and Li-doped KNO was reported in [13,15].…”

“…Ion doping on the K site with Na, Li, Rb, and Cs ions [13][14][15] leads to increasing polarization and band gap, contrary to the case of Nb ion substitution with transition metal ions. The ferroelectric properties of Na-doped KNO were studied within first-principles calculations by Wang et al [13].…”

“…The majority of theoretical papers that have studied the properties of ion-doped KNO are based on density functional theory [11,13,15]. DFT is a very powerful tool for investigating many-body problems.…”