Phase transition and enhanced magneto-dielectric response in BiFeO3-DyMnO3 multiferroics

This work is partially supported by DST fast track Project No. SR/FTP/PS-16/2009. Dhiren K. Pradhan acknowledges IFN (NSF Grant No. EPS—01002410) for fellowship. The work at UPR was supported by National Science Foundation (NSF DMR 1410869) and Institute for Functional Nanomaterials (IFN).We report systematic studies on crystal structure and magneto-dielectric properties of (1 − x) BiFeO3-x DyMnO3 (0.0 ≤ x ≤ 0.2) nanoceramics synthesized by auto-combustion method. Rietveld refinement of X-ray diffraction data indicates a structural transition from R3c to R3c + Pn21a at x = 0.1. Field emission scanning electron micrographs display a decrease in grain size with increase in x. The presence of dielectric anomalies around antiferromagnetic transition temperature implies the magnetoelectric coupling. Dielectric measurements showed decrease in magnetic ordering temperature with increasing x in agreement with differential scanning calorimetry results. A significant increase in magnetization has been found with increasing DyMnO3 substitution. Magneto-impedance spectroscopy reveals a significant change (∼18%) in dielectricpermittivity at H = 2 T for x = 0.2.Peer reviewe

Growth, optimisation and characterisation of pulsed laser deposited Nd-based high temperature superconducting thin films for device applications

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Observation of magnetization reversal behavior in Sm0.9Gd0.1Cr0.85Mn0.15O3 orthochromites

Impact of co-doping (Gd and Mn) on the magnetic properties has been systematically investigated in SmCrO3 compound. For the synthesized compound Sm0.9Gd0.1Cr0.85Mn0.15O3 (SGCMO), below the Neel transition temperature and under low applied magnetic field, temperature induced magnetization reversal at 105 K (crossover temperature) was noticed in the field cooled magnetization curve. Magnetization reversal attained maximum value of -1.03 emu/g at 17 K where spin reorientation occurred. The magnetization reversal disappeared under higher applied field. From the M-H plots an enhancement in the magnetization was observed due to Gd doping. Magnetocaloric effect at low temperatures measured through the magnetic entropy change was found sixteen times higher for this compound as compared to pristine SmCrO3 and twice to that of SmCr0.85Mn0.15O3 compound. The study reveals the importance of co-doping in tailoring the magnetic properties of rare-earth chromites