Study of structural, magnetic and electrical properties on Ho-substituted BiFeO3

The polycrystalline Bi1−xHoxFeO3 (x=0, 0.05, 0.1) compounds were synthesized by conventional solid-state route. Rietveld refinement revealed that all the compounds were stabilized in rhombohedral structure with R3c (IUCr No. 161) space group. Room temperature magnetic measurements revealed that Ho substitution induces ferromagnetism and improves the magnetic properties of BiFeO3. A competing ferro and anti-ferro magnetic interaction was observed in these compounds. Temperature variation of complex impedance studies revealed that electrical properties are improved with the Ho substitution. The ac conductivity found to obey universal power law and showed the negative temperature coefficient of resistance character. Correlated barrier hopping model (CBH) was employed to explain the frequency and temperature dependence of ac conductivity and the mechanism of transport in the material BFO and Ho substituted BFO. Density of states near Fermi level was calculated by using the ac conductivity data.

► BFO and BHFO compounds were synthesized by conventional solid state route.
► Remnant magnetization was enhanced with the substitution of Ho in BFO.
► Neel transition temperatures were almost invariant with the Ho substitution.
► Electric resistivity of the compounds was greatly improved.
► Conduction mechanism was explained on the basis of Correlated barrier hopping model.