Extreme Materials

Figure/Table detail

Corrosion performance of high-entropy (Ho_0.2Er_0.2Tm_0.2Yb_0.2Lu_0.2)₂Si₂O₇ environmental barrier coating material under CMAS conditions at 1500 ℃

Zhang Zhenya, Yuan Shuai, Zhu Zihao, Gao Wei, Meng Yifan, Xue Zhaolu, Xiang Tengfei, Shen Yizhou, Yan Kai, Gyawali Gobinda, Zhang Shihong

Extreme Materials, DOI: 10.1016/j.exm.2026.01.001

Material	Structure	a(Å)	b(Å)	c(Å)	β(°)	Reference
(5RE_0.2)₂Si₂O₇	Monoclinic, C2/m	6.813	8.886	4.702	101.9	This work
Ho₂Si₂O₇	Monoclinic, C2/m	6.875	8.962	4.730	101.7	00-033-0594
Er₂Si₂O₇	Monoclinic, C2/m	6.849	8.940	4.722	101.8	01-082-0733
Tm₂Si₂O₇	Monoclinic, C2/m	6.821	8.906	4.697	101.8	96-223-9661
Yb₂Si₂O₇	Monoclinic, C2/m	6.799	8.876	4.710	102.0	01-082-0734
Lu₂Si₂O₇	Monoclinic, C2/m	6.778	8.880	4.724	102.0	00-034-0509

Table 1 Crystal structure parameters of high-entropy (5RE_0.2)₂Si₂O₇ and individual RE₂Si₂O₇

Other figure/table from this article

Fig.1 Schematic diagram of preparation of (5RE_0.2)₂Si₂O₇ powder and bulk.
Fig.2 XRD patterns (a), Rietveld refinement of XRD pattern (b), Raman spectrum (c), and crystal structure (d) of high-entropy (5RE_0.2)₂Si₂O₇
Fig. 3 Microstructure, EDS maps, and elemental composition of high-entropy (5RE_0.2)₂Si₂O₇ ceramic
Fig. 4 Heat capacity (a), thermal diffusivity coefficient (b), and thermal conductivity (c) of high-entropy (5RE_0.2)₂Si₂O₇ ceramic
Table 2. Thermal conductivity of (5RE_0.2)₂Si₂O₇ and each single principal RE₂Si₂O₇
Fig. 5 TG/DSC curves of high-entropy (5RE_0.2)₂Si₂O₇ from room temperature to 1500 °C
Fig. 6 Schematic diagram of microhardness of high-entropy (5RE_0.2)₂Si₂O₇
Fig.7 XRD patterns of the molten CMAS corrosion of (5RE_0.2)₂Si₂O₇ pellets for different times at 1500℃
Fig.8 Surface morphologies of the molten CMAS corrosion of (5RE_0.2)₂Si₂O₇ pellets for various durations at 1500 °C
Table 3 Atomic ratios (at%) of the corresponding points in Fig. 8
Fig. 9 Cross-sectional microstructures of the molten CMAS corrosion of (5RE_0.2)₂Si₂O₇ pellets for different times at 1500 °C.
Table 4 Atomic ratios (at%) of the corresponding points in Fig. 9
Fig. 10 Cross-sectional microstructures and EDS maps of (5RE_0.2)₂Si₂O₇ and Yb₂Si₂O₇ pellets after CMAS corrosion for 20 h at 1500 ℃
Fig.11 Reaction layer thickness in (5RE_0.2)₂Si₂O₇ ceramic (a), and average apatite formation rate (μm/h^0.5) vs. corrosion time ^0.5 (h^0.5) for Yb₂Si₂O₇ ceramic (b) pellets during CMAS corrosion for different times at 1500 ℃

Title

Figure/Table detail