Dielectric properties of triethylene glycol-stabilized Mn_1−xZn_xFe₂O₄ nanoparticles

Triethylene glycol (TEG) stabilized Mn_1−xZn_xFe₂O₄ nanoparticles were synthesized via a glycothermal reaction. The crystalline structure of nanoparticles were confirmed by X-ray powder diffraction and the surface conjugation of TEG was confirmed by Fourier transform infrared spectroscopy and thermal gravimetric analysis. The ac conductivity (σ_ac), dc conductivity (σ_dc), dielectric permittivity and dissipation factor of the nanocomposites were determined as a function of temperature in the range from 20 to 150 °C at frequencies 1 Hz to 1 MHz. The conductivity measurements reveal that both σ_ac and σ_dc conductivities are strongly temperature dependent. The σ_dc increases significantly with temperature and displays a maximum conductivity of about 8.86 × 10⁻⁷ S cm⁻¹ for x = 0.0 at 150 °C. Study of the real (ε′) and imaginary (ε″) parts of the dielectric permittivity exhibited interfacial polarization and temperature-assisted reorganization effects. - Highlights: • TEG@MnFe₂O₄ nanocomposite was synthesized via a simple polyol route. • Triethylene glycol can serve as a stabilizer to control the particle growth. • VSM confirmed the superparamagnetic character of these nanoparticles. • TEG@MnFe₂O₄ nanocomposite showed thermally activated conductivity.