Synthesis, structure and magnetic properties of layered manganate Sr4Mn3-x Cr x O10 (x=0, 0.2)

The manganates Sr4Mn3-x Cr x O10 (x=0 and 0.2) have been synthesized by solid state reaction. Powder X-ray diffraction analysis shows orthorhombic symmetry with space group Cmca for both compounds. The magnetic susceptibility measurements show an antiferromagnetic transition at 192 and 176 K for x=0 and 0.2, respectively. The magnetic susceptibility data were estimated using a model based on spin exchange antiferromagnetic interactions in isolated (Mn4+) trimer; a paramagnetic contribution due to the chromium ions was added in the case of Cr-doped materials