Abstract
Herein, we report the structural, bonding, dielectric, and electrical transport properties of Ca3(MgTa2)O9 (CMT) and Ca3(ZnTa2)O9 (CZT) with the chemical formula Ca(Mg1/3Ta2/3)O3 and Ca(Zn1/3Ta2/3)O3, respectively, synthesized by the solid-state reaction technique. The Rietveld refinement of powder X-ray diffraction (PXRD) patterns has confirmed that the CMT and CZT are triple perovskites belonging to monoclinic P2 1 /c space group with 1:2 B-site ordering. The unit cell contains four formula units of CMT and CZT. The results of the structural study are corroborated by Fourier transform infrared (FTIR) and Raman spectroscopic studies. Comparing the crystal structures of 1:2 ordered perovskites with the chemical formula Ba(B′1/3B″2/3)O3 and Ca(B′1/3B″2/3)O3, we have predicted that for this group of perovskites, only calcium-based systems exhibit a monoclinic crystal structure of P2 1 /c space group due to the smaller ionic radii of Ca2+ compared to those of Ba2+. The grain size ranges between 0.38 and 2.66 μm for CMT and 0.11 and 1.60 μm for CZT, respectively. The analysis of the dielectric permittivity in the framework of the modified Cole-Cole model has revealed that the dielectric relaxation in CMT and CZT is strongly temperature dependent and polydispersive in nature. The activation energies associated with dielectric and electrical transport properties are ≈0.35 and 0.33 eV for CMT and CZT, respectively. The polaron hopping governs the electrical and dielectric response of the samples. It has been found that CMT and CZT exhibit enhancement in dielectric properties compared to their niobate counterparts and 1:1 ordered tantalum-based perovskite oxides.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
