In this paper,we report on the crystal structure and magnetic properties of the nano structured Baordered phases of rare-earth manganites obtained from the optimally doped solid solutions Ln0.70Ba0.30MnO3(Ln=Pr,Nd).Th...
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In this paper,we report on the crystal structure and magnetic properties of the nano structured Baordered phases of rare-earth manganites obtained from the optimally doped solid solutions Ln0.70Ba0.30MnO3(Ln=Pr,Nd).The materials were studied by X-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy and SQUID-magnetometry *** is found that states with different degrees of cation ordering in the A-sublattice of the ABO3 perovskite can be obtained by employing special conditions of chemical *** particular,reduction of the parent compounds results in the formation of a nanocomposite containing ferrimagnetic anion-deficient ordered phase *** of the composite does not change an average size of the nanocrystallites,but drastically alters their phase composition to stabilize ferromagnetic stoichiometric ordered phase LnBaMn2O6 and ferromagnetic superstoichiometric disordered phase Ln0.90Ba0.10MnO3+δ.It is shown that the magnetic properties of the materials are determined by the joint action of chemical(cation ordering)and external(surface tension)pressures.
The crystal and magnetic structure of solid solutions La0.70Sr0.30MnO3-γ has been investigated by neutron diffraction at different temperatures. Found that the magnetic structure varies depending on the concentration...
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The crystal and magnetic structure of solid solutions La0.70Sr0.30MnO3-γ has been investigated by neutron diffraction at different temperatures. Found that the magnetic structure varies depending on the concentration of oxygen vacancies. These data confirm the theory of the formation of the magnetic phase state in Sr-substituted anion-deficient manganites, whereby in the absence of orbital ordering reduction in coordination of magnetic ions leads to a change in sign of the indirect superexchange interactions Mn3+-O-Mn3+. We discuss the most probable mechanism of formation of the magnetic ordering in Sr-substituted anion-deficient manganites.
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