Molecular field study of the isotopic effect in KH2x D2(1−x)PO4 mixed crystals

Theoretical investigations of thermodynamic properties of partially deuterated K(H_{1-x}D_{x})_{2}PO_{4} ferroelectrics

“…Theoretic studies of the K(H 1−x D x ) 2 PO 4 crystals ware carried out in the works [1][2][3][4][5][6][7][8][9][10][11][12]. All studies of the mixed K(H 1−x D x ) 2 PO 4 ferroelectrics were carried out within one of the modifications of the proton ordering model or within the proton-phonon model.…”

“…Several other model theories related to the study of the dependencies of ferroelectric phase transition temperature and the Curie-Weiss constant on the deuteration level of K(H 1−x D x ) 2 PO 4 crystals emerged after this work, such as [2,3,8,9]. The methods and approaches exploited in the works [2,3] were critically assessed in the work [20].…”

“…The methods and approaches exploited in the works [2,3] were critically assessed in the work [20]. It was noticed that the molecular field approximation used in the works [2,3] is not precise enough.…”

“…The methods and approaches exploited in the works [2,3] were critically assessed in the work [20]. It was noticed that the molecular field approximation used in the works [2,3] is not precise enough. Particularly it concerns the K(H 1−x D x ) 2 PO 4 -type crystals, where this approximation is imprecise even for unmixed compounds and the satisfactory description could be achieved within the cluster approximation.…”