The lanthanium modified lead titanite(PLT) nanocrystals were prepared by sol gel method. The effects of calcination temperature on the crystal size, lattice parameters and c/a ratios of the products have been investig...The lanthanium modified lead titanite(PLT) nanocrystals were prepared by sol gel method. The effects of calcination temperature on the crystal size, lattice parameters and c/a ratios of the products have been investigated by XRD technique. The relation between the crystal size and c/a ratio in terms of lanthanium contents in the modified titanite has been discussed.展开更多
There are no reports about the solubility of the system La （NO<sub>3</sub>）<sub>3</sub>-CH<sub>3</sub>CONH<sub>2</sub>H<sub>2</sub>O in literature yet. In ...There are no reports about the solubility of the system La （NO<sub>3</sub>）<sub>3</sub>-CH<sub>3</sub>CONH<sub>2</sub>H<sub>2</sub>O in literature yet. In order to elucidate the physico-chemical behavior of the system and to provide some necessary data for producing the rare earth metals, we have, in this note, studied the solubility of this system at 0 and 30℃, measured the refractive indexes of the sat-展开更多
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 expr...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.展开更多
文摘The lanthanium modified lead titanite(PLT) nanocrystals were prepared by sol gel method. The effects of calcination temperature on the crystal size, lattice parameters and c/a ratios of the products have been investigated by XRD technique. The relation between the crystal size and c/a ratio in terms of lanthanium contents in the modified titanite has been discussed.
基金Project supported by the National Natural Science Foundation of China.
文摘There are no reports about the solubility of the system La （NO<sub>3</sub>）<sub>3</sub>-CH<sub>3</sub>CONH<sub>2</sub>H<sub>2</sub>O in literature yet. In order to elucidate the physico-chemical behavior of the system and to provide some necessary data for producing the rare earth metals, we have, in this note, studied the solubility of this system at 0 and 30℃, measured the refractive indexes of the sat-
基金This work is supported by the Russian Science Foundation under grant No.19-79-10074.
文摘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.
