Characterization of inclusions inhibiting high thermomiotic behavior of Y₂W₃O₁₂

The present study delves into the significant impact of secondary phases created during the formation process of Y₂W₃O₁₂. Thermomiotic ceramic materials exhibit negative thermal expansion (NTE). Among those ceramics, Y₂W₃O₁₂ is distinct for having phase stability over a high-temperature range as well as high volumetric NTE. These properties make Y₂W₃O₁₂ an unprecedented additive for thermal expansion coefficient (CTE) engineering for high-temperature composites. Synthesis of this material is continuously concluded with a higher thermal expansion than the theoretical. To fully take advantage of this material's unique properties, the origin of the mismatched NTE should be fully understood. In this study, the popular solid-state synthesis approach of Y₂W₃O₁₂ across all synthesis steps was examined in detail. Each secondary Y-W-O phase's contribution to the CTE was calculated, and the final value closely aligns with the measured NTE within 3.7 %, demonstrating the impact of secondary phases on the material's thermal behavior.