Magnetic and hyperfine interactions in HoFe1−xCrxO3 (0≤x≤1) compounds

We report on the magnetic and Mössbauer properties of polycrystalline HoFe1-xCrxO3 (0≤x≤1) compounds. Magnetization data reveals the continuous tailoring of magnetic transition due to weakening of Ho3+-Fe3+ and Fe3+-Fe3+ interactions in the entire temperature range by replacing the Fe3+ ions with Cr3+ ions. The observed decrease in Néel temperature (TN) and increase in spin re-orientation transition temperature (TSR) with the replacement of Fe3+ with Cr3+ is ascribed to the weakening of Fe(Cr)-O-Fe(Cr) antiferromagnetic exchange interaction. In addition, we also attribute such a change in TN to the enhancement of ferromagnetic interaction of adjacent Cr3+ moments through t-e hybridization as a result of the structural distortion. The decrease in isomer shift (IS) suggests enhancement of the interaction between nuclear charge with the 3s electrons as a result of decrease in radial part of 3d wave function with Cr addition. In this paper we also discuss about the variation of quadrupole splitting (QS) and hyperfine fields (Hhf) with Cr addition in HoFe1-xCrxO3 (0≤x≤1) compounds.