Possibilities of Quantum-Chemical Modeling of Domain Boundaries in the Cluster Approximation of the Ising Model for Materials of the Potassium Dihydrogen Phosphate Family

• Published in: Russian journal of inorganic chemistry Vol. 67; no. 8; pp. 1283 - 1289
• Main Authors: Dolin, S. P., Mikhailova, T. Yu, Breslavskaya, N. N.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.08.2022; Springer Nature B.V
• Subjects: Bonding strength; Chemistry; Chemistry and Materials Science; Clusters; Crystal lattices; Deuteration; Domain walls; Ferroelectric materials; Ferroelectricity; Hydrogen bonds; Inorganic Chemistry; Ising model; KDP crystals; Modelling; Potassium phosphates; Quantum chemistry; Theoretical Inorganic Chemistry; Thermodynamic properties; Thermodynamics; ferroelectrics; domains; quantum-chemical modeling
• ISSN: 0036-0236; 1531-8613
• DOI: 10.1134/S0036023622080083

For potassium dihydrogen phosphate and its deuterated analogue, trial versions of model clusters have been proposed to analyze the influence of domain walls on the thermodynamic properties of these ferroelectric materials. Based on the results of quantum-chemical calculations of the energy of these systems, represented as pentameric clusters with 16 strong H-bonds, key reasons for the possible influence of such inhomogeneities have been formulated. Despite the artificial nature of the proposed clusters and the simplified method of their quantum-chemical modeling considering only pseudospin configurations that correspond to the ice rule, three basic factors of the influence of the domain wall on thermodynamics can be assumed. Crucial are the violation (or preservation) of the key features of the symmetry of the crystal lattice, the preservation of the geometric parameters of hydrogen bonds, and the relative concentration of these bonds in domain walls as compared to domains.