Structural and magnetic properties of layered perovskite manganite LaCaBiMn2O7

The layered perovskite oxide, LaCaBiMn 2 O 7 , has been prepared by the conventional aqueous solution precipitation method. The powder X-ray diffraction studies suggest that the phase crystallizes with tetragonal unit cell in the space group I4/mmm. The magnetic properties suggest that the ferromagnetic interactions are dominant and manganese ion in the phase is present in mixed valence states Mn 3+ and Mn 4+ . The thermomagnetization curve is found to obey the Bloch law. Spin wave stiffness constant D and the approximate value for J MnMn exchange interaction were estimated from the experimental results.