Structural, magnetic and thermal study of Cr doped iron-tungsten-oxygen system (Fe₂WO₆)

The structural, magnetic and thermal properties of Cr doped polycrystalline Fe₂WO₆ have been investigated. The Cr doped sample shows tetragonal space group of P4₂/mnm and crystallizes with inverse trirutile structure. All Cr doped samples shows antiferromagnetic-paramagnetic transition (T_N), with increasing Cr percentage the T_N is decreasing to low temperature and finally stable at Cr₂WO₆ antiferromagnetic phase (43 K). The magnetic momentum increases with Cr doping and the strength of antiferromagnetic interaction is decreases due to the decreasing the percentage of half-filled Fe³⁺(3d⁵) e_g orbitals. The heat capacity study on Cr doped samples shows fairly sharp λ-like peak near the ordering temperature indicates the existence of long range antiferromagnetic ordering in the present samples.