Structural, Optical and Magnetic Properties of Multiferroic GdMnO3 Nanoparticles
- 873 Downloads
The structural, optical, and magnetic properties of multiferroic GdMnO3 nanoparticles synthesized by the modified sol–gel route have been investigated. Raman spectroscopy and X-ray diffraction along with Rietveld refinement confirm the pure phase of the GdMnO3 nanoparticles having an orthorhombic perovskite (space group: Pnma) type structure. The morphology was examined by scanning electron microscopy. Energy dispersive spectroscopy confirms the stoichiometry of the composition. The room temperature UV-visible absorption spectrum using Tauc’s relation gives an optical band gap of ∼2.9 eV. A magnetization study of the GdMnO3 nanoparticles was performed over a temperature range of 2–300 K at an applied field of 0.05 T by using a vibrating sample magnetometer. An effective magnetic moment (μ eff) of ∼9.2μ B was obtained. The system is paramagnetic at room temperature and shows a ferromagnetic-like nature at 2 K as the applied magnetic field aligns the Gd moments and the contribution of the net moment of Gd spins is larger than that of the anti-ferromagnetically canted state of the Mn spins.
KeywordsMultiferroic X-ray diffraction Rietveld refinement Raman spectroscopy Vibrating sample magnetometer
The authors would like to acknowledge UGC-DAE-CSR, Indore centre, India, for providing the XRD, Raman, and VSM facilities. P. Negi is also thankful to Dr. Alok Banerjee, Dr. V.G. Sathe, and Dr. Mukul Gupta for their valuable suggestions.
- 7.Choi, W.S., Kim, D.G., Seo, S.A., Moon, S.J., Lee, D., Lee, J.H., Lee, H.S., Cho, D.Y., Lee, Y.S., Murugavel, P., Yu, J., Noh, T.W.: Electronic structures of hexagonal RMnO3 (R=Gd, Tb, Dy, and Ho) thin films: optical spectroscopy and first-principles calculations. Phys. Rev. B 77, 045137 (2008) ADSCrossRefGoogle Scholar
- 11.Ferreira, W.S., Moreira, J.A., Almeida, A., Chaves, M.R., Araújo, J.P., Oliveira, J.B., Silva, J.M.M.D., Sa, M.A., Mendonca, T.M., Carvalho, P.S., Kreisel, J., Ribeiro, J.L., Vieira, L.G., Tavares, P.B., Mendonca, S.: Spin-phonon coupling and magnetoelectric properties: EuMnO3 versus GdMnO3. Phys. Rev. B 79, 054303 (2009) ADSCrossRefGoogle Scholar
- 12.Morrish, A.H., Zhou, X.Z.: Magnetic nanometer systems and Mossbauer spectroscopy. In: Hadjipanayis, G.C., Prinz, G.A. (eds.) Science and Technology of Nanostructured Magnetic Materials, pp. 511–532. Plenum, New York (1991) Google Scholar
- 16.Kittel, C.: Introduction to Solid State Physics. Wiley, New York (1976) Google Scholar