Magnetic and electrical transport properties of YbFe2O4

We present magnetic and electrical transport properties such as resistivity, magnetoresistance, dielectric, and polarization of polycrystalline YbFe₂O₄ . The ferrimagnetic transition temperature is measured at 243 K, followed by the two low-temperature transitions at ∼190 and ∼65 K, respectively. The magnetic properties including the M -H hysteresis loops exhibit a strong temperature dependence and possibly indicate a spin-glass state below 65 K for YbFe₂O₄ . The iron Mössbauer measurement at 295 K confirms the presence of two Fe sites. The measured resistivity can be modeled with the Mott's variable-range hopping model, ρ ∝exp(T^{₀/T ) 1 /4} , indicating the electron hopping between Fe^{2 +} and Fe^{3 +} sites. The magnetoresistance effects up to 6% at 8 T were observed and the effects could be caused by the field-induced changes in the electron-hopping processes. The frequency-dependent complex dielectric constant has been found to be strongly influenced by the contact effects, and the polarization of polycrystalline YbFe₂O₄ does not show ferroelectricity.