Structural and magnetic properties of Mn doped Ho<inf>2</inf>O<inf>3</inf> nanocrystalline

Abstract

Ho2-xMnxO3 (HMO), x = 0.0, 0.05, 0.10, 0.15 and 0.20 have been prepared as solid solutions in the nano form. The cation distribution and structural changes upon Mn doping are studied using X-ray diffraction and Infrared (IR) spectroscopy. The results indicate that, the diffraction patterns resemble a single phase solid solution of bixbyite structure type for x = 0.0 to 0.10, while for x ≥ 0.15 two phases were detected for HMO; bixbyite structure and hexagonal phase with space group P 63 cm. Random cationic distribution between the two sites 8b and 24d was obtained for x = 0.15, while preferential accommodation for other values of x was found. The effect of Mn addition on the magnetic susceptibility was investigated using SQUID magnetometer in the temperature interval from 5 K to 300 K under a magnetic field of 200 Oe. Negative values for curie paramagnetic temperatures, θ, were obtained, which indicates an antiferromagnetic interaction between the magnetic ions in HMO. The value of θ increases then decreases with increasing Mn doped amount, which can be correlated with the cation distribution.