Effect of Pr doping on the properties of Bi0.5-xPrxCa0.5MnO3 (0 ≤ x ≤ 0.50) manganites

In this work, we report the temperature dependent electron spin resonance (ESR) and magnetization (M) studies of Bi0.5-xPrxCa0.5MnO3 (0 <= x <= 0.50) manganites synthesized by the sol gel method. The x-ray diffraction (XRD) data analysis indicates that 6s(2) lone pair character of Bi3+ ions is dominant in undoped sample and it changes to constrained type when doped with Pr at Bi site. The charge ordering temperature (T-co) decreases from 327 K to 250 K as x increases from 0 to 0.15. The T-co value remains at similar to 250 K with further increase in Pr content. The nonlinear behavior of ESR signal linewidth (Delta H) as a function of temperature above T-co, observed for doped samples is an indication of strengthening of electron spin lattice interactions. The sharp rise in M value below 45 K for undoped sample and below 115 K for doped samples is characteristic of ferromagnetic (FM)-cluster glass behavior. The results are discussed in view of the effects of Pr doping on 6s(2) lone pair character of Bi3+ ions, disorder in the system and changes in the surface/volume ratio of the grains. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.