Please use this identifier to cite or link to this item:
|Title:||Dielectric anomaly and magnetic order in Ba(Mn₀․₅Nb₀․₅)O₃|
|Authors:||Mishra, R K|
Choudhary, R N P
Thakur, Awalendra K
|Abstract:||The polycrystalline barium manganese niobiate Ba(Mn₀․₅Nb₀․₅)O₃ has been prepared by a solid state reaction technique. The formation of single phase compound is confirmed by an X-ray diffraction analysis. The surface morphology examined through scanning electron microscope (SEM) confirmed polycrystalline texture of the material. Detailed studies of dielectric properties are carried out at different temperatures (23-350°C) and in a wide frequency range of 10²-10⁶ Hz . A dielectric anomaly with transition temperature at 283°C is observed. The real and imaginary part of permittivity (Ɛ' and Ɛ") were found to be strongly frequency and temperature dependent. The variation of ac conductivity with inverse of absolute temperature is found to obey Arrhenius law. The activation energy in lower temperature range was found to be 0.19 eV and its value in higher temperature range was 0.87 eV. Magnetization as a function of temperature from 2 K to 300 K is measured in different fields in both zero-field cooled (ZFC) and field-cooled (FC) mode. An antiferromagnetic transition is observed at 7 K. Non-linear M-H and a finite opening in the hysteresis loop at 2 K substantiate the presence of ferromagnetic component in the antiferromagnetic matrix.|
|Appears in Collections:||IJEMS Vol.15(2) [April 2008]|
Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.