tailieunhanh - A study of optical and magnetoelectric properties of BaTi1−xNixO3

The shift in Raman and change in absorption spectra are evidence that would relate to the structure change or disorder and impurity in the samples. From the above results, a critical substituent content at which the structural phase change takes place is shown. | JOURNAL OF SCIENCE OF HNUE Mathematical and Physical Sci. 2012 Vol. 57 No. 7 pp. 44-50 This paper is available online at http A STUDY OF OPTICAL AND MAGNETOELECTRIC PROPERTIES OF BaTi1 x Nix O3 Nguyen Van Khanh Faculty of Physics Hanoi National University of Education Abstract. We present the results of X-ray diffraction XRD Raman scattering absorption impedance spectroscopy and magnetization studies of Ni2 -doped BaTi1 x Nix O3 . Some Ba atoms were replaced by Ni with x atoms in the range of - . XRD analysis of these samples indicates a change in the cell parameters with doping content and there appears an abnormal point at x . Our main focus is the Raman peak vs. Ni content which have separated peaks in the range of 450 cm 1 - 600 cm 1 . The shift in Raman and change in absorption spectra are evidence that would relate to the structure change or disorder and impurity in the samples. From the above results a critical substituent content at which the structural phase change takes place is shown. We also present the impedance spectroscopy and magnetization vs. magnetic field to elucidate the role of dopant in the BaTi1 x Nix O3 samples. Keywords BaTi1 x Nix O3 Raman scattering absorption impedance spectroscopy magnetization. 1. Introduction Multiferroic materials are of great scientific and technological interest due to their magnetoelectric properties originating from the coupling between ferroelectric and ferromagnetic order parameters 10 . The interplay between ferroelectricity and magnetism allows a magnetic control of ferroelectric properties and an electric control of magnetic properties and could yield new device concepts such as ferroelectric and multiferroic tunnel junctions 13 . Barium titanate BaTiO3 is a ferroelectric material widely studied because of its many potential useful properties. The phase of BaTiO3 at room temperature is a Received October 15 2011. Accepted February 23 2012. Physics Subject Classification 62 44 07