Cation disorder and size effects on the magnetic transition in Ba-containing ferromagnetic manganites

The results of 55Mn NMR, dc magnetization, and ac susceptibility studies are presented for La0.7Ca0.15Ba0.15MnO3, La0.7Sr0.15Ba0.15MnO3, and La0.7Ba0.3MnO3 ferromagnetic manganites. While TC is a function of the mean radius of the La and alkaline-earth ions and the cation disorder, the form of the temperature dependence of the magnetic moment may be expressed as function of TC only. The phase transition is continuous for all three compounds.