Modifications in magnetic properties of BiMn2O5 multiferroic using swift heavy ion irradiation

Department of Physics, Aligarh Muslim University, Aligarh 202002, India
Journal of Applied Physics (Impact Factor: 2.18). 06/2010; 107(9):09D903 - 09D903-3. DOI: 10.1063/1.3360356
Source: IEEE Xplore


We report the near edge x-ray absorption fine structure (NEXAFS) and x-ray magnetic circular dichroism (XMCD) studies at the Mn L 3,2 edge of pulsed laser deposited pristine thin films of multiferroic BiMn 2 O 5 . These investigations are furthermore testified for BiMn 2 O 5 thin films irradiated through 200 MeV   Ag 15+ ions with fluence value 5×1011 ions / cm 2 . Though the pristine film is primarily antiferromagnetic in nature, irradiation induces ferrimagnetism in it. Element specific characterizations, NEXAFS and XMCD demonstrate the evolution of Mn 2+ state piloting to magnetic signal associated with it.

Download full-text


Available from: Pardeep K. Thakur
  • [Show abstract] [Hide abstract]
    ABSTRACT: The swift heavy ion �SHI� irradiation induces weak ferrimagnetism �FM� in magnetically frustrated polycrystalline BiMn2O5 thin films. This is manifested from irradiation induced higher energetic configuration that accounts for evolution of the Mn2+ state in the Mn3+ /Mn4+ network. Basically, this is the root of large magnetic moment in the irradiated samples. X-ray diffraction and Raman-scattering data of the samples indicate considerable modifications in the crystal structure after the SHI irradiation. FM in the irradiated samples and magnetically frustrated behavior of the pristine sample is apparent from dc magnetization measurements. Element specific characterizations such as near-edge x-ray absorption fine structure spectroscopy at O K and Mn L3,2 edges along with x-ray magnetic circular dichroism at Mn L3,2 edge show the evolution of the Mn2+ at disbursement of the Mn4+. The microscopic origin behind the induced weak FM is found to be the increased orbital moment in the irradiated thin films.
    No preview · Article · Nov 2010 · Physical Review B
  • [Show abstract] [Hide abstract]
    ABSTRACT: Inspection of multiferroicity in BiMn2 − xTixO5 (0 ≤ x ≤ 0.30) (BMTO) ceramics is performed through specific heat and Raman spectroscopic studies. Thermal variation of specific heat (C) (in the absence and presence of fixed magnetic fields up to 14 T) and Raman spectra of BMTO are presented. In the temperature variation of C, a remarkable anomaly at the antiferromagnetic (AFM) ordering temperature (TN ~ 39 K) is observed in all samples. Pure BiMn2O5 (for x = 0.0) exhibits a larger specific heat anomaly at TN compared to that of Ti substituted samples, both in the presence and absence of external magnetic fields. The excess specific heat (ΔC) versus T clearly illustrates appreciable anomalies at ~ 86 and ~ 120 K in Ti doped samples related to the magnetic and dielectric transitions, respectively. The low temperature specific heat (LTSH) data indicate a considerably improved ferromagnetic contribution in samples with higher Ti concentration (x > 0.15). The Raman spectra of the doped samples at different fixed temperatures validate the strong electron–phonon coupling corresponding to the observed magnetism and increased harmonicity at dielectric transitions.
    No preview · Article · Nov 2010 · Journal of Physics Condensed Matter
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This review discusses recent efforts to control magnetism with electric fields in single and multilayer oxides, which has great potential to improve a variety of technological endeavors, such as magnetic sensing and magnetoelectric logic. The importance of electrical control of magnetism is followed by a discussion of multiferroics and magnetoelectrics, which are the leading contenders for this task. The focus of this review is on complementary methods in understanding the magnetoelectric coupling, an essential step to electrical control of magnetism. Neutron scattering, nonlinear optics and x-ray spectromicroscopy are addressed in providing key parameters in the study of magnetoelectric coupling. While primarily direct (single-phase multiferroics) magnetoelectric materials are used as examples, the techniques discussed are also valuable to the study of indirect (e.g., multilayers and pillars) magnetoelectrics. The review concludes with a summary of the field and future directions.
    Full-text · Article · Jan 2011 · International Journal of Modern Physics B
Show more