Tetragonal structure and dielectric behaviour of rare-earth substituted La0.8Co0.16-xEu0.04GdxTiO3 (x = 0.04–0.16) nanorods

Abstract

La0.8Co0.16-xEu0.04GdxTiO3 (LCEGT) (x = 0.04–0.16) nanorods were synthesized via low temperature hydrothermal process. The X-ray diffraction studies revealed that the formation of tetragonal structure along with the secondary phases of α-Eu2TiO3. The lattice parameters, unit cell volume were observed to be decreased with the increase of Gd3+ from 0.04 to 0.16, and X-ray density increased from 11.01 to 11.67 g/c.c. with the Gd3+ composition. FESEM and TEM images confirmed the formation of mixed morphology consisting of nanorods and nanospheres in all samples. The dielectric analysis studied in-between frequencies 10 kHz–8 MHz discovered that the dielectric constant decreases from 4653 to 306 with the increase of Gd3+ composition from 0.04 to 0.12. The dielectric loss at 1 MHz was observed to be decreased from 223 to 28 with the increase of Gd3+ in the sample. The ac-conductivity increases from 0.0015 to 0.0223 S/cm with the increase of frequency from 10 kHz to 8 MHz for the Gd3+ = 0.04 sample. The impedance and dielectric modulus formalism were studied as a function of composition and frequency. The conduction process is through the grains in place of grain boundaries and non-Debye type of relaxations revealed from Cole-Cole plots. The studied properties of LCEGT nanorods indicate that the material is suitable for dielectric absorber and charge stored capacitor applications.