Nanoscale Surface Engineering of Yttria-Stabilized Zirconia for Enhanced Optoelectronic and Structural Performance

This study investigates the nanoscale surface modifications and phase stability of yttria-stabilized zirconia (YSZ) under different mechanical polishing treatments, with implications for optoelectronic and structural applications. Four commercial YSZ ceramics (Cercon, Upcera, Weiland, Diazir) were subjected to grinding and polishing using EVE, KOMET, TOB, and SF systems, followed by comprehensive X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) analyses. The EVE polishing system achieved the lowest surface roughness (Ra: 0.18–0.65 μ m), while TOB produced the highest roughness (0.80–1.12 μ m), attributed to inefficient abrasive-binder interactions. XRD confirmed the retention of the tetragonal phase (t-ZrO 2 ) without transformation to monoclinic (m-ZrO 2 ), indicating thermal and mechanical stability under processing conditions. XPS analysis revealed yttrium redistribution, with Cercon exhibiting the highest yttrium content (4.79 at.%), suggesting superior structural integrity due to optimized yttria doping. SEM imaging demonstrated nanoscale scratch patterns, where EVE-polished surfaces exhibited minimal defects, whereas TOB-treated samples showed deep grooves and non-uniform textures, impacting optical scattering and mechanical durability. These findings highlight the critical role of surface engineering in controlling nanoscale roughness and phase stability, which are essential for optoelectronic applications where smooth, defect-free surfaces enhance light transmission and minimize scattering losses. The study provides foundational insights into YSZ’s potential as a high-performance dielectric and protective coating in nanoelectronic devices, emphasizing the need for optimized polishing protocols to ensure long-term reliability in both biomedical and optoelectronic systems.