PHYSICS AND MATHEMATICS

Study of Mn concentration effect on phase-formation, dimensions and optical properties of BiFe$_{1-x}$Mn$_x$O$_3$ nanoparticles

Luu Thi Nhan^a, Pham Mai An^b, Ngo Thi Hoa^a, Nguyen Quang Thanh^a, Nguyen Van Manh^a, Duong Vu Truong^a, Le Thi Binh^b, Nguyen Thanh Trung^c, Nguyen Van Chuong<sup>d

a</sup> Ha Noi University of Industry
^b Thai Nguyen University of Education
^c Thai Nguyen Teacher Training College
^d Donghoa hight school

Abstract: Nanoscale multiferroic powders BiFe$_{1-x}$Mn$_x$O$_3$ ($x = 0.00, 0.05, 0.075$) synthesized by the sol-gel method are the object of the study. Samples are calcined at appropriate temperatures and for a specified period. Phase analysis of the samples is performed with the use of x-ray diffraction (XRD). The morphology of BiFe$_{1-x}$Mn$_x$O$_3$ ($x = 0.00, 0.05, 0.075$) powder particles is investigated using a scanning electron microscope (SEM). The spectra of UV-visible absorption of the samples are obtained using a spectrophotometric system Cary 5000 UV-Vis-NIR Spectrophotometer. The results show that Mn doping with a certain ratio will help to remove the secondary phase and create samples with single-phase BFO, and this will lead to a decrease in particle size. The study of the absorption spectra in the UV-visible region of the fabricated samples showed that Mn doping expanded and shifted the absorbing edge of the samples towards large wavelength, and reduced the width of the forbidden band. This will increase the photocatalytic activity of the BFO material system, which will make the application more practical.

Keywords: bismuth ferrite, multiferroic, phase composition, microscopic structure, the absorption spectrum.

DOI: 10.23670/IRJ.2019.84.6.004