Anomalous magnetic ordering of C3 and Kondo-like effect in the double-exchange ferromagnet (Pr0.1Ce0.4Sr0.5) MnO3

We report evidence for the occurrence of a Kondo-like effect and anomalous magnetic ordering of cerium in a double-exchange ferromagnet (Pr-0.1,Ce0.4S r0.5)MnO3. Neutron-diffraction measurements show that this material undergo es a first-order transition from an orthorhombic (Imma) to a tetragonal (I4 /mcm) structure that is accompanied by a ferromagnetic transition, as tempe rature decreases. At about 250 K, a bulk ferromagnetic metallic transition occurs below which the manganese moments remain ordered ferromagnetically d own to 1.5 K. Below T= 100 K, the Ce moments are ordered antiferromagnetica lly with respect to the ferromagnetic Mn moments and thus form a ferrimagne tic ground state. The temperature dependence of resistivity rho(T) shows an omalous behavior; it increases with decrease of temperature and shows a max imum at T similar to 120 K and a minimum at T similar to 15 K in contrast t o the metallic behavior expected due to larger W and the double-exchange fe rromagnetism. This behavior of resistivity and the antiferromagnetic orderi ng of cerium with the ferromagnetic Mn moments suggest a Kondo-like effect in a spin-polarized conduction-electron system. [S0163-1829(99)04325-8].