Quantum-mechanical model for estimating the number ratio between different valence cations in multiatom compounds

Abstract

A quantum-mechanical potential barrier model for estimating the number ratio between different valence cations in multiatom compounds is proposed. It is supposed that there is a potential barrier between a cation-anion pair. The height of the potential barrier is proportional to the ionization energy of the cation, and the width of the potential barrier is related to the distance between neighboring cations and anions. As examples for using this model, the distribution of cations with different valences in some ABO3 lanthanum manganites is explained satisfactorily.

Study of the structure, magnetic properties and free energy of the three phase composites La0.7−y−zSr0.3−xMn1−δ/3O3−δ/(La2O3)y/2/(La(OH)3)z

“…Colossal magnetoresistance (CMR) materials [1][2][3][4] with the general formula Ln 1−x M x MnO 3 , where Ln is the lanthanide cation and M is usually an alkaline-earth cation, have attracted much attention because of their potential applications in magnetic sensors, data storage, and other applications, such as the cathodes of the solid oxide fuel cells [5][6][7] (SOFCs) and microwave dielectric materials [8][9][10]. These materials possess an ABO 3 perovskite structure.…”

Roles of Te and Mn in the two phases of manganite with nominal composition La0.6Sr0.1Te x MnO3

“…Besides, due to the fact that the third and fourth ionization energies of Te are 27.96 eV and 37.41 eV respectively, which are larger than the third ionization energy (19.18 eV) of La and the second ionization energy (11.03 eV) of Sr, Te 4+ cannot form at La sites. We have presented previously a quantum-mechanical potential barrier model to estimate the number ratio between different valence cations in multi-atom compounds [4]. According to this model, we can estimate the probability of Te 3+ appearing at La sites as…”

“…[1][2][3][4][5]. However, there are still some unresolved problems concerning manganites doped with tetravalent cations [6][7][8][9][10][11].…”

Quantum mechanical method for estimating ionicity of spinel ferrites

“…In earlier works [13][14][15][16], we proposed a quantum-mechanical method for estimating the cation distribution in cubic spinel ferrites, where materials were treated as ionic compounds without covalent bonds. In this paper, using both magnetization and density of states calculated by the density functional theory, ionicity of cubic spinel ferrite Fe 3 O 4 is determined.…”