4 research outputs found
Modification of the ground state in Sm-Sr manganites by oxygen isotope substitution
The effect of O O isotope substitution on electrical
resistivity and magnetic susceptibility of SmSrMnO manganites
is analyzed. It is shown that the oxygen isotope substitution drastically
affects the phase diagram at the crossover region between the ferromagnetic
metal state and that of antiferromagnetic insulator (0.4 0.6), and
induces the metal-insulator transition at for = 0.475 and 0.5. The nature
of antiferromagnetic insulator phase is discussed.Comment: 4 pages, 3 eps figures, RevTeX, submitted to Phys. Rev. Let
Isotope effect for transport and magnetic properties of La
The effect of isotope substitution on electrical resistivity,
magnetoresistance, and ac magnetic susceptibility was studied for La0.35Pr0.35Ca0.3MnO3
epitaxial thin films deposited onto LaAlO3 and SrTiO3 substrates. For the films on LaAlO3, the
isotope substitution resulted in the reversible transition from a metal-like to insulating state. The
applied magnetic field () transformed the sample with 18O back to the metallic state.
The films on SrTiO3 remained metallic at low temperatures for both 16O and 18O, but the
shift of the resistivity peak corresponding to onset of metallic state exceeded
63 K after substitution. The temperature dependence of both resistivity and magnetic
susceptibility was characterized by hysteresis, especially pronounced in the case of the films on
LaAlO3. Such a behavior gives certain indications of the phase separation characteristic of interplay
between ferromagnetism and charge ordering