Effect of Fe supplantation on structural and dielectric properties of La2CoMnO6

• Published in: Materials chemistry and physics Vol. 294; p. 127012
• Main Authors: Sharma, Reena, Hooda, Neelam, Hooda, Ashima, Khasa, Satish
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.01.2023
• Subjects: Cation disorder; Dielectric constant; Perovskites; Rietveld refinement; VRH conduction; Dielectric constant; VRH conduction; Perovskites; Rietveld refinement; Cation disorder
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2022.127012

Double Perovskite system La2Co1-xFexMnO6 (x = 0, 0.2, 0.5, 0.8 and 1.0) has been synthesized by sol-gel route. XRD profiles confirmed the absence of any external phase in pure La2CoMnO6 phase. Rietveld refinement analysis confirmed the existence of monoclinic (ordered) as well as rhombohedral and orthorhombic (disordered) structures. Lattice parameters and unit cell volume are found to increase with increase in Fe content. Morphological and compositional analysis was done using FESEM with EDS. Frequency and temperature dependent dielectric characterization revealed the dispersion of both dielectric constant as well as loss tangent at low frequency and high temperature. The Nyquist plot of impedance (cole-cole) revealed negative temperature coefficient of resistance (NTCR) behavior of prepared samples and suggest a non-Debye type relaxation in these samples. An increasing trend with increase in frequency and temperature was exhibited by ac conductivity. Variation of dc electrical conductivity with temperature suggested a semiconducting behavior which can be explained by both small polaron hopping (SPH) and variable range hopping (VRH) conduction mechanisms. •Rietveld refinement unveiled presence of monoclinic (ordered) along with rhombohedral and orthorhombic (disordered) phases.•Dielectric constant and ac conductivity show dependency on cationic disorder along with frequency and temperature.•Frequency dependence of ac conductivity studied using double power law.•DC conductivity variation revealed presence of Variable range hopping and Small polaron hopping conduction mechanisms.