The equation of state for metal-doped ferroelectrics within the Weiss model  

作　　者：Ivan A.Starkov Mikhail A.Mishnevy Alexander S.Starkovz 

机构地区：[1]All-Russian Research Institute of Fats,Chernyakhovskij st.10.,191119 St.Petersburg,Russia [2]Saint-Petersburg Eletroechnical University“LET”Professora Popova st.5,197376 St.Petersburg,Russia [3]ITMO University,Kronverksky pr.49,197101 St.Petersburg,Russial

出　　处：《Journal of Advanced Dielectrics》2022年第4期36-41,共6页先进电介质学报（英文）

基　　金：This work is supported by the Russian Science Foundation under grant No.19-79-10074.

摘　　要：This paper presents a theoretical model for describing the thermodynamic properties of doped ferroelectric crystals based on a modifed Weiss mean-field approach.Accounting for quadrupole and octupole terms in the expression for the effective field within the Weiss model makes it possible to move from the Langevin equation to the Landau--Ginzburg equation.Furthermore,the cofficients of the Landau-Ginzburg equation can be expressed in terms of the physical parameters of the crystal lattice.For these parameters,analytical ex pressions are proposed that describe their change when adding dopants in ceramic matrix composites.Perovskite barium titanate ceramics with a variety of inclusions is considered as an application example of the developed method.The obtained agreement between the analytical and experimental results for barium titanate ceramics with lanthanum/magnesium/zirconium dopants gives us hope of the applicability of the present theory to the calculation of other doped ferroelectrics as well.

关 键 词：FERROELECTRICS doped ceramics Weiss theory Ising model barium titanate lanthanium magnesium ZIRCONIUM 

分 类 号：TB31[一般工业技术—材料科学与工程]