Detailed investigations on structural properties and transport mechanism governed in Nd1−xCdxMnO3

• Published in: Journal of materials science. Materials in electronics 2018-05, Vol.29 (10), p.8107-8134
• Main Authors: Kanjariya, P. V., Jadav, G. D., Saravanan, C., Govindaraj, L., Arumugam, S., Bhalodia, J. A.
• Format: Article
• Language: English
• Subjects: Adiabatic flow; Cadmium; Characterization and Evaluation of Materials; Chemistry and Materials Science; Doping; Electrical resistivity; Gravimetric analysis; Hopping conduction; Lattice strain; Magnetoresistance; Magnetoresistivity; Materials Science; Optical and Electronic Materials; Properties (attributes); Specific heat; Structural analysis; Synthesis; Temperature; Temperature dependence; Transport
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-018-8817-6

In this paper, we report the results of detailed investigation on structural properties and transport mechanism governed in Nd 1−x Cd x MnO 3 manganites for x = 0.0, 0.1, 0.2, 0.3 and 0.4 synthesized using modified combustion method at sintering temperature of 1000 °C. EDAX measurements were taken for elemental analysis which confirm the stoichiometry and success of doping. To understand thermal reactions in precursors, thermo gravimetric analysis was carried out. Intrinsic nature of synthesized compounds was confirmed using FTIR data. XRD measurements were carried out to understand structural properties of the synthesized compounds through Rietveld analysis in the light of calculated various structural parameters. Williamson–Hall method was used for the calculation of crystallite size and lattice strain in the synthesized compounds. Results obtained through structural analysis show increment in octahedral distortion and octahedral tilting in Cd-doped compounds. To understand the morphology of all the samples, SEM analysis was carried out which indicates increment in grain size with Cd doping concentration. Resistivity and magnetoresistance measurements were obtained at various temperatures to understand conduction mechanism. Obtained resistivity data were fitted in various theoretical models to understand the governing conduction mechanism in the synthesized compounds. Temperature dependent resistivity fitting shows that the conduction mechanism follows non-adiabatic and small-polaron hopping above θ D /2 (θ D is the Debye temperature) and Mott-type variable range hopping below θ D /2. Obtained results indicate density of states at Fermi level which increase with magnetic field. Higher MR% was observed in Cd-doped compounds in comparison with pure NdMnO 3 compounds.