Structural and Dielectric Properties of Yttrium Doped Multiferroic Bismuth Ferrite (Bi_(1-x)Y_xFeO_3, x = 0, 0.18) Synthesized by Sol-Gel Method

摘要

Pure and Y-doped BiFeO_3 have been synthesized by sol–gel method. the gel have been heated at 150°C for 3 h, the low-temperature heating treatment was given to obtain uniform, homogenous, and smaller size. The crystal BiFeO_3 have been found after dried and grounded followed by calcination at 750°C for 4 h. The X-ray diffraction (XRD) patterns of pure and Y-doped BiFeO_3 are indexed and well matched with rhombohedral structure (R3c) and have been found secondary impurities such as Bi_2Fe_4O_9 (mullite) and Bi_(25)Fe_2O_(39) (sillenite) were detected in pure and Bi_(1-x)Y_x·FeO_3 (x=0, 0.18). The pattern of (104) and (110) peaks in Y-doped BiFeO_3 around 2θ = 32°indicates reduction of the rhombohedral phase and increase that of the orthorhombic phase (Pbnm). Morphology of pure and Y-doped BiFeO_3 with FE-SEM the result doping Yttrium can be reduce particle size between 200 – 400 nm. The LCR study, the impedance (real and imaginer) BiFeO_3 and Y doped decreasing at low frequency (40 – 2 kHz) but after frequency 2 kHz is constant value. The impedance (imajiner) of pure is smaller of Yttrium doped BiFeO_3. The dielectric constant pure and Ydoped BiFeO_3 have been constan after frequency 2 kHz and decreasing at low frequency (40 – 2 kHz). The conductancy pure BiFeO_3 is smaller of Y doped BiFeO_3 at 42 Hz – 5 MHz and after frequency 2 kHz conductancy of Y doped increases significant.