FTIR and Electrical Study of Dysprosium Doped Cobalt Ferrite Nanoparticles

Abstract

We have studied the role of Dy 3+ doping on the XRD, TEM, FTIR, and dielectric and electrical properties of CoFe 2 O 4 at room temperature. Cubic spinel phase of CoFe 2− x Dy x O 4 (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:math> = 0.00, 0.05, 0.10, and 0.15) was synthesized by using different sintering temperatures (300, 500, 700, and 900°C). The two absorption bands ν 1 and ν 2 are observed in Fourier transform infrared spectroscopy (FTIR) spectra corresponding to the tetrahedral and octahedral sites, which show signature of spinel structure of the sample. For the sample sintered at 300°C, the dielectric constant is almost unchanged with the frequency at the particular concentrations of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:math> = 0.00 and 0.05. Similar result is obtained for the sample sintered at 500°C (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:math> = 0.10, 0.15), 700°C (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:math> = 0.05, 0.10, and 0.15), and 900°C (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:math> = 0.05, 0.10). An increase in the dielectric constant was observed for the undoped cobalt ferrite sintered at 500, 700, and 900°C. The values of electrical resistivity of the materials vary from ~10 5 to 10 9 Ω-cm.