Effect of calcium-deficiency upon physical properties of La_(0.6)Ca_(0.4)MnO_3

摘要

Structural and magnetic properties of the calcium-defect La_(0.6)Ca_(0.4-x)□_xMnO_3 (0 ≤ x ≤ 0.2) perovskite manganites have been investigated. Our powder samples have been prepared by the conventional solid state reaction technique at high temperature. Rietveld analysis show that all our synthesized samples crystallize in the orthorhombic perovskite structure with Pnma space group. The Mn atom is coordinated by six oxygen atoms forming an irregular octahedron. With decreasing Ca content the unit cell volume increases. Magnetic measurements as a function of temperature show that all our samples exhibit a paramagnetic-ferromagnetic transition with decreasing temperature.