Structure and mechanical properties of hyper-hardened solid solutions Li_0.12Na_0.88Ta_yNb_1–yO₃

Abstract

An influence of hyper-hardening on structure and mechanical properties of ceramic solid solutions (SS) Li_0.12Na_0.88Ta _y Nb_{1– y} O₃ with tantalum concentrations у = 0.05; 0.25; 0.4 has been revealed. The researched was carried out using X-ray diffraction and scanning probe microscopy methods. Two ferroelectric phases co-exist in initial non-hardened SS Li_0.12Na_0.88Ta _y Nb_{1– y} O₃: hexagonal R3cH and rhombic P2₁ma. A symmetric rhombic phasePbnm prevails in hardened samples. Hyper-hardening has been established to sufficiently increase micro-hardness and surface strength of SSLi_0.12Na_0.88Ta _y Nb_{1– y} O₃ceramic samples.

Keywords:

• Hyper-hardening
• solid solutions
• perovskites
• space group
• microstructure
• crack growth resistance

Additional information

Funding

This work was supported by the Ministry of Science and Higher Education Russian Federation scientific topic No 0226-2019-0038 (registration # АААА-А18-118022190125-2) and by the Development program of the Petrozavodsk State University for 2017–2021 years.