Physical Properties of New, Lead Free BaTi_{1 − x}(Nb_0.5Yb_0.5)_xO₃ Ceramics

Abstract

New lead free ceramics derived from the ferroelectric material BaTiO₃ by substituting Ti^{4 +} by Nb^{5 +} and Yb^{3 +}. The dielectric and ferroelectric properties were studied. The compositions BaTi_{1 − x} (Nb_0.5Yb_0.5) _x O₃ display a classical ferroelectric (0 ≤ × < 0.1) and relaxor ferroelectric behaviour (0.1 ≤ × ≤ 0.2). BaTi_0.9(Nb_0.5Yb_0.5)_0.1O₃ specimen present a relaxor behaviour at a temperature close to room with high permittivity (ε′ _r = 9500 at 1 kHz), which opens the way for possible use of it for capacitor applications. The polarisation hysteresis loops were observed of relaxor BaTi_0.875(Nb_0.5Yb_0.5)_0.125O₃ specimen. The ceramic BaTi_0.9(Yb_0.5Nb_0.5)_0.1O₃ provides a piezoelectric constant d₃₁ of about 11.17 pC/N near room temperature.

Keywords:

• Dielectric properties
• ferroelectric
• ytterbium
• relaxor
• Piezoelectric