Study On Synthesis And Properties Of Perovskite Manganites

At present, the influence of doping rare earth elements on the resistant effect ofCa₄Mn_3-xNb_xO₁₀ attracts lots of attention. This paper makes research on the increasing ofCMR effect via the increasing of doping quantity. The charge order is destroyed and theFerromagnetism is enhanced, while the size of particles is decreased.This paper applies the high temperature solid state method, synthesizesCa₄Mn_3-xNb_xO₁₀(x = 0, 0.06, 0.15,å’Œ0.2) doped with the ion Nb⁵⁺, uses sol-gel method tomake Pr_0.45Ca_0.55MnO₃, in which the ion Nb⁵⁺ is added so as to increase the CMR effect. Thispaper also makes research on the effect of decreasing sample particles on changing thecharge order and magnetic features.With the increasing of the ion Nb⁵⁺, when Ca₄Mn_3-xNb_xO₁₀ reaches x=0.2, T arrives at40K, and CRM reaches the maximum point 51%. With the decreasing of the size of particles,when Pr_0.55Ca_0.45MnO₃ is 50nm, the charge order is destroyed with the decreasing ofparticles, which equips the samples with much stronger Ferromagnetism.