Relaxor or classical ferroelectric behaviour in ceramics with composition Ba_1-xNa_xTi_1-xNb_xO₃

Abstract

Ceramics with composition Ba1-xNaxTi1-xNbxO3 are of either classical ferroelectric (for 0 ⩽ x < 0.075) and ferro- or antiferroelectric (for 0.55 < x ⩽ 1) or relaxor ferroelectric type (for 0.075 ⩽ x ⩽ 0.55), the transition at Tc being only diffuse without any frequency dispersion for this last region. All the corresponding dielectric characteristics, i.e. diffusivity of the ferroelectric-paraelectric transition, frequency dispersion of ε'r, shift of Tm with frequency deviation from the Curie-Weiss law, are determined. The relaxor behaviour is more relaxor the more the composition deviates from BaTiO3 and NaNbO3. This study is in the field of preparation of relaxor ceramics free from lead in the interest of the environment, which present a transition temperature close to room temperature.

Dielectric and Raman studies of Ba0.06(Na1/2Bi1/2)0.94TiO3–NaNbO3ceramics

“…Recently, the dielectric and relaxor behavior of BaTiO 3 -NaNbO 3 [20], A 0.5 Bi 0.5 TiO 3 -NaNbO 3 (A = Li, Na, K, Ag) [21], BaSnO 3 -NaNO 3 [22], Sr 0.5 NbO 3 -LiNbO 3 -NaNbO 3 [23], (Bi 0.5 Na 0.5 ) 0.94 Ba 0.06 (Ti 1 − 5x/4 Nb x )O 3 [24] and (Bi 0.5 Na 0.5 ) 0.935 Ba 0.065 Ti (1 − x) Nb x O 3 -0.01SrZrO 3 [25] ceramic solid solutions have been studied. Xu et al [26] have studied the phase transitions, formation enthalpies and implications for general perovskite energetics with special reference to SrTiO 3 -NaNbO 3 solid solution, while magnetic and ferroelectric phase transitions studies in BiFeO 3 -NaNbO 3 system were carried out by Raevski et al [27].…”

Structure and optical properties of [Ba1–xY2x/3](Zr0.25Ti0.75)O3 powders

“…In spite of this interesting electrical property, the main drawback is related to its considerable dielectric loss at high frequencies [10e13]. The barium zirconate titanate Ba(Zr x Ti 1ex )O 3 (BZT) has received more attention in the field of materials science by reason of its structural and physical properties exhibit a significant dependency with the titanium (Ti) and zirconium (Zr) contents into the matrix [14,15]. In fact, the researches with this perovskite [16e18] have been mainly focused on the dielectric properties as well as on the phase transition from ferroelectric to relaxor.…”

Phase formation and dielectric study of Bi doped BaTi0.75Zr0.25O3 ceramic

“…Researchers are directed towards more environmentally friendly lead-free relaxor materials. In this way, many compositions with perovskite structure were recently prepared and characterized [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Among this ceramics, researchers have shown their interest in the solid solution system Ba(Ti 1Àx Zr x )O 3 with different concentrations of Ti and Zr [19][20][21][22].…”