TY - JOUR
T1 - Orthorhombic to tetragonal polymorphic transformation of YTa3O9 and its inhibition through the design of high-entropy (Y0.2La0.2Ce0.2Nd0.2Gd0.2)Ta3O9
AU - Liu, Hanwen
AU - Liu, Ling
AU - Xiang, Huimin
AU - Dai, Fu Zhi
AU - Wang, Xiaohui
AU - Huang, Muzhang
AU - Wan, Chunlei
AU - Ma, Zhuang
AU - Liu, Yanbo
AU - Li, Hezhang
AU - Zhou, Yanchun
N1 - Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2022/7
Y1 - 2022/7
N2 - To explore the mechanism of phase transformation, YTa3O9 was prepared by an integrated one-step synthesis and sintering method at 1500 °C using Y2O3 and Ta2O5 powders as starting materials. High-temperature XRD patterns and Raman spectra showed that a phase transformation from orthorhombic to tetragonal took place in YTa3O9 through the bond length and angle changes at 300–400 °C, which caused a thermal conductivity rise. To inhibit the phase transformation, a high-entropy (Y0.2La0.2Ce0.2Nd0.2Gd0.2)Ta3O9 (HE RETa3O9) was designed and synthesized at 1550 °C using the integrated solid-state synthesis and sintering method. In tetragonal structured HE RETa3O9, phase transformation was inhibited by the high-entropy effect. Furthermore, HE RETa3O9 exhibited low thermal conductivity, and its tendency to increase with temperature was alleviated (1.69 W/m·K, 1073 K). Good phase stability, low thermal conductivity and comparable fracture toughness to YSZ make HE RETa3O9 promising as a new thermal barrier coating material.
AB - To explore the mechanism of phase transformation, YTa3O9 was prepared by an integrated one-step synthesis and sintering method at 1500 °C using Y2O3 and Ta2O5 powders as starting materials. High-temperature XRD patterns and Raman spectra showed that a phase transformation from orthorhombic to tetragonal took place in YTa3O9 through the bond length and angle changes at 300–400 °C, which caused a thermal conductivity rise. To inhibit the phase transformation, a high-entropy (Y0.2La0.2Ce0.2Nd0.2Gd0.2)Ta3O9 (HE RETa3O9) was designed and synthesized at 1550 °C using the integrated solid-state synthesis and sintering method. In tetragonal structured HE RETa3O9, phase transformation was inhibited by the high-entropy effect. Furthermore, HE RETa3O9 exhibited low thermal conductivity, and its tendency to increase with temperature was alleviated (1.69 W/m·K, 1073 K). Good phase stability, low thermal conductivity and comparable fracture toughness to YSZ make HE RETa3O9 promising as a new thermal barrier coating material.
KW - High-entropy ceramics (HECs)
KW - Integrated synthesis and sintering
KW - Phase transformation
KW - Rare-earth tantalate
KW - Thermal barrier coatings (TBCs)
UR - http://www.scopus.com/inward/record.url?scp=85126137120&partnerID=8YFLogxK
U2 - 10.1016/j.jeurceramsoc.2022.03.005
DO - 10.1016/j.jeurceramsoc.2022.03.005
M3 - Article
AN - SCOPUS:85126137120
SN - 0955-2219
VL - 42
SP - 3559
EP - 3569
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 8
ER -