Aqueous alkaline suitable gel system and related mechanism for highly transparent La_0.4Gd_1.6Zr₂O₇ ceramic preparation

Abstract

In this work, a fabrication route combined optimized ISOBAM-104/TAC gelcasting (where TAC refers to triammonium citrate) and one-step sintering technology was developed to prepare highly transparent La x Gd 2-x Zr 2 O 7 (LGZO) ceramics. The gelling behavior in an alkaline environment was investigated, and the corresponding mechanism was systematically proposed for the advanced spontaneous gel system. The starting materials after ball milling were directly shaped into green bodies without any treatment, and high-quality LGZO ceramics were obtained by three-stage debinding and one-step sintering. The in-line transmittance of these ceramics reaches 74% at 1100 nm, which is about 95% of the theoretical value. This work not only establishes an efficient method to fabricate LGZO ceramics in large and complex shapes but also elucidates the gelling mechanism in alkaline, which expands the application of gel-casting technology in transparent ceramics.

Effect of CaO doping on densification and microstructure control of highly transparent La0.4Gd1.6Zr2O7 ceramics

“…The mixed powders were obtained by calcination at 900°C for 2 h in the air to remove residual impurities. The detailed procedures were shown in our previous work 11 …”

“…As a representative member of pyrochlore rare‐earth zirconate (RE 2 Zr 2 O 7 ), the transparent La 2− x Gd x Zr 2 O 7 ceramics possess excellent properties like high temperature resistance, 4 high refractive index, 5 and low phonon energy 6 . La 2− x Gd x Zr 2 O 7 is generally considered an interesting material, owing to its various attractive applications, such as thermal barrier coatings, 7 window materials, 8 optical lens, 9,10 and irradiation shielding 11–14 . As for the majority of these fields, the high transparency and high relative density are the critical properties 15 …”

“…More recently, Liang et al. successfully fabricated the La 0.4 Gd 1.6 Zr 2 O 7 ceramics with T = 74% at 1100 nm 11 . The transparency has been only about 95% of the theoretical transmittance and still has space for improvement.…”

“…6 La 2−x Gd x Zr 2 O 7 is generally considered an interesting material, owing to its various attractive applications, such as thermal barrier coatings, 7 window materials, 8 optical lens, 9,10 and irradiation shielding. [11][12][13][14] As for the majority of these fields, the high transparency and high relative density are the critical properties. 15 In recent years, intensive efforts have been made in the powder preparation and sintering process to promote the transparency and density of La 2−x Gd x Zr 2 O 7 ceramics.…”

“…More recently, Liang et al successfully fabricated the La 0.4 Gd 1.6 Zr 2 O 7 ceramics with T = 74% at 1100 nm. 11 The transparency has been only about 95% of the theoretical transmittance and still has space for improvement. Thus, to promote the industrialization and commercial application, it is essential to improve the optical quality and combine the simple fabricating process at the same time.…”