Effect of Alkali Elements Content on the Structure and Electrical Properties of (K_0.48Na_0.48Li_0.04)(Nb_0.90Ta_0.04Sb_0.06)O₃ Lead‐Free Piezoelectric Ceramics

Abstract

In this communication, we report on the effects of alkaline elements (K, Na, and Li) content on the electrical properties of (K0.48Na0.48Li0.04)(Nb0.90Sb0.06Ta0.04)O3 ceramics. Because of the high volatility, the alkaline elements evaporate during the high‐temperature sintering process, generating vacancy defects in the ceramics. As a result, the ferroelectric and piezoelectric properties of the ceramics become weakened. Our results reveal that the volatilization loss can be effectively compensated by a 1 mol% excess of alkaline elements. The remanent polarization Pr, piezoelectric coefficient d33, and electromechanical coupling coefficient kp of the compensated ceramics are improved by 15%, 16%, and 20%, respectively, having a value of 30 μC/cm2, 310 pC/N, and 0.6.

Phase transition, electrical and luminescent properties of Dy-doped K0.5Na0.5NbO3-based lead-free ceramics

“…4a, two dielectric peaks for the ceramics with x = 0 are observed at 62 and 328°C, respectively. Our previous studies have confirmed that the first peak (T O-T ) at 62°C is ascribed to the transition from orthorhombic to tetragonal phase, while the second peak T C at 328°C is related to that from cubic to orthorhombic phase [11]. As shown in Fig.…”

“…for A-sites ions and/or B-sites ions [8][9][10]. Our previous study has shown that the (K 0.48 Na 0.48 Li 0.04 ) (Nb 0.90 Ta 0.04 Sb 0.06 )O 3 ceramic exhibits excellent ferroelectric and piezoelectric properties because of the coexistence of orthorhombic and tetragonal phases [11]. On the other hand, with the rapid development of electronic/microelectromic devices towards miniaturization and multifunctionalization, multifunctional materials have attracted considerable attention.…”

Crystal structure and properties of K0.5Na0.5NbO3–Bi0.5Na0.5TiO3–LiSbO3 lead-free piezoelectric ceramics

“…Our research indicated that the KNN-(Bi 0.5 Na 0.5 )TiO 3 ceramics with small amounts of LiSbO 3 exhibited the excellent piezoelectric properties when 1 mol% (Bi 0.5 Na 0.5 )TiO 3 was added. Many researches have been focused on the KNN-LiSbO 3 systems [17][18][19][20][21]. But few reports are involved with the solid solutions of K 0.5 Na 0.5 NbO 3 -Bi 0.5 Na 0.5 TiO 3 -LiSbO 3 system, and the effect of LiSbO 3 on the properties of the K 0.5 Na 0.5 NbO 3 -Bi 0.5 Na 0.5 TiO 3 -LiSbO 3 ceramics remains unclear.…”

Phase transition and electrical properties of (1−x)K0.02Na0.98NbO3–xBaTiO3 ceramics

“…Although the maximum dielectric constant at the Curie temperature (ε m ) for K2NN is quite low, ε m increased markedly with increasing BaTiO 3 content. K2NNBT10 ceramics has the largest ε m (>10,000) which is even higher than that of doped K 0.5 Na 0.5 NbO 3 ceramics [4,5]. Fig.…”

“…Different dopants are studied to improve their piezoelectric properties, including Li + , Ta 5+ , Sb 5+ , Bi(Zn 0.5 Ti 0.5 )O 3 , BaTiO 3 , etc. [4][5][6][7][8]. BaTiO 3 modified K 0.5 Na 0.5 NbO 3 ceramics were studied by many researchers.…”