Open AccessEPR study of Mn site substituted Pr based Doped Rare Earth Manganites
Author(s) -
Dinesh Uthra,
Meena Sharma
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2070/1/012035
Subject(s) - electron paramagnetic resonance , valency , valence (chemistry) , divalent , crystallography , impurity , doping , analytical chemistry (journal) , materials science , chemistry , nuclear magnetic resonance , metallurgy , physics , linguistics , philosophy , optoelectronics , organic chemistry , chromatography
In this paper, we present the investigations of Electron Paramagnetic Resonance (EPR) on Mn site substituted Pr based Doped rare Earth Manganites i.e. Pr 0.60 Ca 0.40 MnO 3 and Pr 0.60 Ca 0.40 Mn 0.85 Zn 0.15 O 3 . Changes in physical properties as lattice parameters, average valence of Mn site was observable of those manganites. X-ray diffraction pattern shows that both Pr 0.60 Ca 0.40 MnO 3 and Pr 0.60 Ca 0.40 Mn 0.85 Zn 0.15 O 3 have single phase and without the other secondary or impurity phase and indexed supported the Pbnm space group. The value of x in Pr0.60Ca0.40Mn1-xZnxO3 increases, the average valence V was increased except for a fixed composition, i.e. x remains unchanged, the average valence V was decreased as we go from less valency to high valency (i.e., from divalent to trivalent and from trivalent to tetravalent. The EDXS analysis of those materials shows good homogeneity, but there are experimental errors in composition. It is seen from the SEM images that is formed in different shape grains. The average grain sizes of the samples are different for Pr 0.60 Ca 0.40 MnO 3 and Pr 0.06 Ca 0.40 Mn 0.85 Zn 0.15 O 3 The paramagnetic resonance spectra parameters (effective g-factor, peak-to-peak line width) of Pr 0.60 Ca 0.40 MnO 3 and Pr 0.60 Ca 0.40 Mn 0.85 Zn 0.15 O 3 .have been used to study the paramagnetic spin correlations and spin dynamics. As for Pr 0.60 Ca 0.40 MnO 3 the line width becomes wider because of the contribution of small polaron jumping within the PM mechanism. However, as for Pr 0.60 Ca 0.40 Mn 0.85 Zn 0.15 O 3 the broadening of EPR line-width is understood with the spin-lattice relaxation mechanism, g value decreased from 1.99 to 1.79. Therefore, the Zn dopant not solely changes the parent spin correlation in the PM regime however additionally suppresses the development of orbital ordering.