Investigation of site selectivity of lanthanum in SrBi4Ti4O15 ceramic by structural, dielectric, ferroelectric and conduction behavior

Abstract

This manuscript reports the structural and electrical properties of Lanthanum substituted strontium bismuth titanate with general formula SrBi 4-x La x Ti 4 O 15 (where 0 B x B 0.25), prepared by solid-state reaction route. X-ray diffraction study shows a single phase orthorhombic structure in all the compositions. It was also observed that the lattice parameter increases up to x = 0.15 and then decreases with further La content. The Raman spectra shows the distribution of lanthanum into the perovskite layers and (Bi 2 O 2 ) 2? layers of SrBi 4 Ti 4 O 15 ceramic. The temperature dependent dielectric study reveals that the transition temperature and maximum dielectric constant decreases with La content. The broadening of the phase transition was observed with La substitution due to the decrease in octahedral distortion. Impedance analysis confirms the presence of two semicircular arcs in doped samples, suggesting the existence of grain and grain-boundary conduction. The P-E loop study shows that both the remnant polarization (P r ) and the coercive field increases with the increasing La content up to x = 0.15 and thereafter decreases to lower values with further La content. Similar kind of trend is also observed in DC conductivity.

Effect of CuO modification on dielectric, ferroelectric and piezoelectric properties of lead-free SrBi4Ti4O15 ceramics

“…For improving the properties of SBTi, researchers have been studied the effect of doping in various site of SBTi with different metal ions. Reports are available with lanthanum [4], praseodymium [5], erbium [6] barium [2] calcium [7], zirconium [8] niobium [9][10][11], vanadium [12], cobalt [13], tungsten [14], and molybdenum [10] doped SBTi systems.…”

Molten salt synthesis of SrBi4-xLaxTi4O15 (X = 0.05, 0.10, 0.15, and 0.20) for Rhodamine-B degradation

“…Substitution of La 3+ ion into Bi 3+ sites on the perovskite layer responsible for x= 0.05-0.15 and resulted in decreased orthorhombic distortion in the crystal lattice because of the lack of lone-pair electron. On the other hand, the x= 0.20 replaced Bi3+ on the bismuth layer, causing structure instability; thus, higher SrTiO3 was formed [15,17]. It can be seen that platelike particles were formed.…”

“…SrTiO3 phase was found as an impurity, detected from 2θ = 32,4° peak on all samples. Difficulties on singlephase synthesis of lanthanum doped SrBi4Ti4O15 was caused by instability resulted from higher lanthanum concentration doping since it can replace Bi 3+ -sites on the bismuth layer [1,14,15]. 1 resulted from multiphase Rietveld refinement from their diffractograms using ICSD-No.…”

Co-Precipitation Synthesis and Characterization of SrBi2Ta2O9 Ceramic

“…For random access memory applications, it is necessary to obtain the SrBi 2 Ta 2 O 9 materials with low dielectric loss, low conductivity and high fatigue properties. 9 To prevent the volatilization of Bi 2 O 3 during sintering above 1000°C, which could result in oxygen and bismuth vacancies, it is therefore desirable to dope SrBi 2 Ta 2 O 9 by rare earth elements. 10,11 Meanwhile, an accurate amount of Bi 2 O 3 oxide must be added to compensate experimentally for the loss characteristics of the Bi 2 O 3 oxide.…”