Room-Temperature Flash Sintering of Lanthanum Chromate Through Co-Doping

doi:10.16552/j.cnki.issn1001-1625.2026.0107

Abstract

Abstract:

Doped lanthanum chromite ceramics possess high electrical conductivity and excellent high-temperature stability， demonstrating broad application prospects. However， lanthanum chromite materials are difficult to densify. In order to lower their sintering temperature and simplify the fabrication process， this paper applied the flash sintering technique to the preparation of this type of material. The effects of Co ion single doping and A/B-site Ca-Co ions co-doping on the structure， intrinsic properties， and flash sintering behavior of lanthanum chromite were investigated. The results indicate that， compared with LaCr_0.8Co_0.2O₃， further doping with Ca²⁺ induces oxygen vacancies and optimizes the charge carrier characteristics. The rapid migration driven by the electric field reduces the threshold value conditions required for the onset of flash sintering， thereby ultimately enabling the rapid sintering of La_0.9Ca_0.1Cr_0.8Co_0.2O₃ ceramics under a low electric field at room temperature. A fully dense structure is achieved after flash sintering for 60 s. Additionally， the fabrication efficiency is substantially improved compared to conventional high-temperature sintering at 1 650 ℃. This study elucidates the modulating effect of doping on the flash sintering behavior at low temperature of lanthanum chromite， offering a feasible pathway for the room-temperature sintering of functional ceramics of this type. It also provides experimental evidence and a theoretical reference for the application of direct-current flash sintering technology in the energy-efficient preparation of ceramic materials.

Key words: lanthanum chromate, room-temperature flash sintering, co-doping, oxygen vacancy, threshold value, direct-current electric field

CLC Number:

TQ174.6⁺5

GUAN Lili, WU Li, SI Zhipeng, BIAN Ziheng. Room-Temperature Flash Sintering of Lanthanum Chromate Through Co-Doping[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2026, 45(8): 2882-2889.

Figures/Tables 8

Fig.1 Schematic diagram of material synthesis and flash sintering process

Fig.2 XRD Rietveld refinement plots of powders

Table 1 Crystal structure information

Crystal	LCC	LCCC
Space group	Pnma	Pnma
a/Å	5.431 84	5.407 90
b/Å	7.736 02	7.725 33
c/Å	5.500 48	5.485 39
Unit cell volume/Å³	231.135	229.168

Fig.3 Current density as a function of ambient temperature under different electric field strengths

Fig.4 Microstructure of samples under different sintering conditions

Fig.5 Band gap comparison of samples

Fig.6 XPS spectra of LCC and LCCC

Table 2 Species content and proportion corresponding to quantitative calculation of O 1s

Sample	O_lat atomic fraction/%	O_ads atomic fraction/%	O_ads/O_lat
LCC	51.14	46.74	0.91
LCCC	46.08	49.93	1.08

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