Interaction between the magnetic moments of the 3d and the 4f electrons in manganite, probed by Ga substitution

The substitution of Ga for Mn in manganite Nd0.6Dy0.1Sr0.3MnO3 with a ferromagnetic (FM) ground state has been performed to study the influence of the Mn-sublattice magnetic ordering on the magnetic rare-earth sublattice. It is found that the substitution of Mn3+ with Ga3+ ions results in a sharp decrease of TC, reflecting the reduction of the double-exchange interactions strength JMn–Mn. At the same time, a depinning effect of the rare-earth magnetic moment has been observed. This behavior unambiguously proves that the exchange interaction between Mn and rare-earth ions JMn–R strongly influences the rare-earth magnetic ordering at temperatures below TC and stabilizes the rare-earth magnetic ground state.