Crystal structure, microstructure, thermal expansion and electrical conductivity of CeO₂–ZrO₂ solid solution

Abstract

CeO 2 -ZrO 2 solid solution was synthesised by mechanical activation solid-state chemical reaction method and characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal dilatometer, Hebb-Wagner method and DC van der Pauw method. The effects of CeO 2 content on the crystal structure, microstructure, thermal expansion coefficient (TEC), electronic conductivity and total conductivity were investigated. XRD analysis showed that (25 and 75 mol-%) CeO 2 -ZrO 2 solid solutions corresponded to tetragonal and cubic phase, and 50 mol-% CeO 2 -ZrO 2 belonged to the mixture of tetragonal and cubic phases. SEM analysis showed that doping CeO 2 was helpful to the sinterability of CeO 2 -ZrO 2 samples. The TECs increased from 13.27 × 10 −6 to 14.72 × 10 −6 K −1 with increasing CeO 2 content. The electronic and total conductivities of 75 mol-% CeO 2 -ZrO 2 were largest, reaching 1.02 × 10 −4 S cm −1 and 1.02 × 10 −2 S cm −1 at 850°C, respectively.

Stability of doped zirconia under extreme conditions: Toward long‐term and secure storage of radioactive waste

“…Increase in corresponding coefficients was also reported for CeO 2 -ZrO 2 solid solution upon the introduction of cerium ions. 19 This behavior was explained by reduced strength in Zr-O bonding due to the substitution of larger Ce 4+ for smaller Zr 4+ in the host ZrO 2 lattice (ionic radii of 0.97 vs. 0.84 Å, respectively, in eightfold coordination 20 ). The Zr-O bonds with reduced energy are more affected by temperature increase with resulting increase in CLTEs.…”

Interdiffusion between gadolinia doped ceria and yttria stabilized zirconia in solid oxide fuel cells: Experimental investigation and kinetic modeling

“…The CGO-YSZ interdiffusion process results in elemental redistribution and increased 4 resistivity. Several studies have presented the formation of solid solution phase between YSZ and CGO and the ohmic resistant depending on the mixing composition after high temperature sintering [14][15][16][17][18][19][20][21]. Tsoga et al [16] reported that the interdiffusion phenomenon at the CGO-YSZ interface occurs already at 1200 ºC.…”

“…As the temperature increases from 1300 ºC to 1550 ºC [14][15][16][17][18][19], the observed solid state reaction and interdiffusion occurring at the CGO-YSZ interface become more serious. Conductivity measurements on the mixed solid solution have been performed at various temperatures [20][21][22]. It was found that the ionic conductivity of the mixed solution phase decreases due to partial substitution of YSZ with CGO, reaching a minimum at the composition of CGO0.5YSZ0.5 and then increasing again to reach that of CGO for complete substitution of CGO for YSZ.…”

Effect of ZrO2 whiskers on the microstructure and mechanical properties of a Ti(C,N)‐based cermet cutting tool material

“…ZrO 2 belongs to the class of high‐temperature oxide ceramics, which exhibit many favourable functions, such as an exceptionally high melting point, excellent chemical inertness, excellent thermal insulating properties and a fracture toughness of 2600 MPa at room temperature . Therefore, it is hypothesized that ZrO 2 whiskers can provide potential reinforcing and toughening whiskers in cermets to enhance the mechanical properties.…”