In this work, lithium ferrite (Li0.5Fe2.5O4) nanoparticles were prepared via mechanochemical processing and subsequent heat treatment at a relatively low (600 °C) calcining temperature. The raw materials used were high purity Fe2O3 and Li2CO3 that were milled for between 2 and 20 h. The milled powders were then calcined at temperatures of 500 and 600 °C for 5 h in air. XRD results show that optimum conditions to obtain single phase lithium ferrite nanoparticles with a mean crystallite size of about 23 nm, using Scherrer’s formula, are 10 h milling and calcination at 600 °C. Saturation magnetization and coercivity of the single phase Li ferrite
nanoparticles are 44.6 emu/g and 100 Oe respectively, which are both smaller than those of the bulk Li ferrite. The Curie temperature of the single sample was determined by a Faraday balance, which is 578 °C and smaller than that of bulk Li ferrite.