Investigation on electrical conductivity and dielectric property of La_(0.8)Pb_(0.2)(Fe,Ti)_(0.5)O_(3)ceramic nanoparticles

The modification of the structure lanthanum orthoferrites(LaFeO_(3))to obtain ceramic materials with enhanced structural,optical,and electrical properties constitutes an active area of research.The preparation of La_(0.8)Pb_(0.2)(Fe,Ti)_(0.5)O_(3)(LPFTO)ceramic nanoparticles by following a cation substitution approach from LaFeO_(3)using sol–gel and sintering methods is described.The electrical and dielectric properties of the obtained material are investigated.The contribution of grain and grain boundary in the conduction mechanism is demonstrated by complex impedance analysis.The LPFTO ceramic nanoparticles exhibit a giant dielectric constant of the order of 108.The conductivity analysis suggests the occurrence of thermally activated semiconductor behavior.Moreover,the ferromagnetic–paramagnetic semiconductor transition temperature is observed at 385 K.The ac conductivity behavior satisfies the nonoverlapping small-polaron tunneling(NSPT)model.

Effect of Sr-substitution on the structural and dielectric properties of LaFeO_(3) perovskite materials

The study aims to investigate the structural and dielectric properties of perovskite La_(1-x)Sr_(x)FeO_(3)(x=0.1,0.2,0.3,and 0.4)synthesized by solgel and sintering methods.X-ray diffraction(XRD),transmission electron microscopy(TEM),and LCR-Meter were used to identify the phase,crystallography parameters,morphology,particle size,and electrical behavior of the synthesized perovskite materials.The samples showed a single-phase orthorhombic crystal structure with Pbnm space group.Sr-substitution induced the volume unit cell and crystallite size to decrease.The synthesized nanoparticles were uniform and homogeneous with the particle size less than 200 nm.Impedance spectroscopy(IS)was used to explain the electrical behavior as a function of frequency(100 Hz to 1 MHz)at various temperatures(300–373 K).The presence of small polarons as charge carriers within the grain and grain boundary were elucidated from the electrical conductivity experiments.Sr-substitution caused the dielectric constant and electronic conductivity to increase with the highest values obtained from La_(1-x)Sr_(x)FeO_(3)(x=0.4).

Characterizing temperature dependent complex electrical impedance analysis of LaFe_(1−x)Zn_(x)O_(3)(x=0.03,0.05,and 0.07)ceramics

followed by sintering-annealing treatments to form the bulk-phase.X-ray diffraction analysis revealed that all ceramics were crystallized in the orthorhombic perovskite structure with Pbnm symmetry.Grain size distribution and morphological characteri-stics were investigated by scanning electron microscopy.Specific surface area was analyzed through BET-BJH methods.Electrical impedance analysis was investigated as a function of frequency at various temperatures.It was found that the electrical behavior is dominated by grain boundary contribution,i.e.,electrical conductivity.The frequency dependence of the complex conductivity was analyzed through Joncher’s power law and the dominance of translational motion with a sudden hopping mechanism in the electrical conduction mechanism increased with increasing Zn content.Activation energy decreased with increasing Zn content.