Le Fu,Bohan Wang,Ying Deng,Guofu Xu,Jiwu Huang,Håkan Engqvist,Wei Xia
Liquid-phase sintering (LPS) is an effective pathway to assist the densification of ceramics. However, it has seldom been used to densify glass–ceramics. In the present study, a multielement co-doping strategy has been utilized to achieve LPS of a ZrO 2 –SiO 2 nanocrystalline glass–ceramic. Compared with undoped samples densified by solid-state sintering, doping of equimolar Al, Y, and Ca promoted the densification of the glass–ceramic at lower temperatures with a faster densification rate. Ternary doping enhanced coarsening of ZrO 2 nanocrystallites during sintering and annealing. The distribution of dopants was carefully observed with X-ray energy-dispersive spectrometry technique in scanning electron transmission microscopy mode. Results showed that the three dopants showed different distribution behaviors. After sintering, Y dopants were predominately distributed in ZrO 2 nanocrystallites, whereas parts of Al and Ca dopants were distributed in ZrO 2 nanocrystallites and part of them co-segregated at the ZrO 2 /SiO 2 heterointerfaces. Meanwhile, the segregation of Ca dopant at some intergranular films among ZrO 2 nanocrystallites was observed. Redistribution of dopants did not occur during annealing.
JunHan Ma,Shaoyi Chang,Di Qiu,Haijun Mao,Xiaoqin Ke
Relaxor ferroelectrics (RFE) serve as superior alternatives to ferroelectrics (FE) for energy storage owing to their enhanced energy storage efficiency and thermal stability. This study combines experimental characterization and phase-field simulations to systematically investigate the effects of dopant distribution on the energy storage properties of RFEs. By analyzing the microstructure evolution and key performance metrics—including characteristic temperatures ( T f , T m , T B ), recoverable energy storage density ( W rec ), and dielectric constant ( ε r )—we establish a phase-field model incorporating diffusive compositional distribution of the dopant to reveal the underlying mechanisms of RFE behavior in 0.9BaTiO 3 -0.1Bi(Mg 2/3 Ta 1/3 )O 3 (0.9BT-0.1BMTa). Experimental results confirm frequency dispersion and characteristic relaxor behavior, while simulations reveal that dispersed BMTa concentrations enhance W rec stability on temperature at the expense of peak values, with optimal performance occurring between the dielectric maximum temperature ( T m ) and Burns temperature ( T B ). The local electric field is shown to moderately improve thermal stability but exerts less influence than compositional distribution. For practical energy storage applications , we propose design protocols: (1) prioritize concentrated dopant distributions if high W rec or fixed-temperature operation is required, and (2) adopt widely dispersed dopants for broad temperature-range stability. These findings provide a quantitative framework for tailoring perovskite-structured RFEs via compositional engineering, balancing performance metrics for targeted device specifications.
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