Elaboration of CaLa₂S₄ transparent ceramics from novel precursor powders route

Odile Merdrignac-Conanec (1) , Guillaume Durand (1) , Sebastian Walfort (1) , Noha Hakmeh (1) , Xianghua Zhang (1)

1 ISCR - Institut des Sciences Chimiques de Rennes

A cost-effective processing route for the production of calcium lanthanum sulfide CaLa₂S₄ (CLS) via a novel fast fabrication of precursor powders is reported. The sinterability of the newly developed powders was investigated by use of Hot-Pressing and pressureless sintering. Complementary techniques (XRD, SEM-EDS, chemical analysis, SSA, FT-IR spectroscopy) were employed to correlate the sintering processes and parameters to the microstructural/compositional developments and optical performances of the densified ceramics. Dense (>99.8% theor.) and homogeneous CLS ceramics were produced by pressureless sintering at 1250°C for 12 h in H₂S followed by hot-pressing at 1000°C for 6 h in a powder bed to prevent sulfur loss. Transparency free of impurity absorption has been achieved in the LWIR region (optical transmission of 51% in the 12-14 mm range).

Mots clés: transparent ceramic; combustion synthesis; sintering; calcium lanthanum sulfide

Domaines: Matériaux

Odile Merdrignac-Conanec, Guillaume Durand, Sebastian Walfort, Noha Hakmeh, Xianghua Zhang. Elaboration of CaLa₂S₄ transparent ceramics from novel precursor powders route. Ceramics International, 2017, 43 (8), pp.5984-5989. ⟨10.1016/j.ceramint.2017.01.132⟩. ⟨hal-01458361⟩