Exploring weak ferromagnetism and conduction mechanism in the layered oxide BiPbSr2MnO6

• Published in: Journal of materials science. Materials in electronics Vol. 32; no. 1; pp. 923 - 931
• Main Authors: Mohapatra, S. R., Sahu, B., Kaushik, S. D., Behera, Gurudayal, Singh, A. K.
• Format: Journal Article
• Language: English
• Published: New York Springer US 2021; Springer Nature B.V
• Subjects: Antiferromagnetism; Atmospheric models; Characterization and Evaluation of Materials; Chemistry and Materials Science; Crystal structure; Cuprates; Ferromagnetism; Frequency analysis; Frequency domain analysis; Magnetic transitions; Materials Science; Optical and Electronic Materials; Photoelectrons; Room temperature; Spectrum analysis; Transition temperature
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-020-04869-4

Layered oxide BiPbSr
2
MnO
6
(BPSMO), isostructural to 10 K Bi-based cuprates, is prepared by employing solid-state route in nitrogen atmosphere. Phase purity of the compound is determined from the room temperature Rietveld refined X-ray diffraction (XRD) data. BPSMO crystallizes in an orthorhombic crystal structure, thereby confirming its space group as
‘A2aa’
. Presence of weak ferromagnetism in BPSMO below magnetic transition temperature (T
N
) is validated from isothermal magnetization data accompanied by the Arrott plot at 2.8 K, in contrast to its antiferromagnetic behavior at 290 K. The coexistence of Mn
2+
and Mn
3+
is confirmed from X-ray photoelectron spectroscopy study. The conduction mechanism in BPSMO is studied following two different hopping models, i.e., Arrhenius model for T > 250 K and Mott's variable range hopping (MVRH) model for T < 250 K. The relaxation in BPSMO is found to be polaronic in nature and may have originated due to the mixed valence structure of the sample. Lastly, the frequency domain analysis of dielectric spectra reveals the presence of two distinct relaxations. Moreover, it is determined that the low-frequency and high-frequency relaxation have activation energy 0.35 eV and 0.48 eV, respectively.