Magnetic relaxation phenomena and cluster glass properties of La 0.7 − x Y x Ca 0.3 MnO 3 manganites

By Rafael S. Freitas, L. Ghivelder, F. Damay, F. Dias, L. Cohen. 2000

182 citations recorded by the source corpus.

The dynamic magnetic properties of the distorted perovskite system ${\mathrm{La}}_{0.7\ensuremath{-}x}{\mathrm{Y}}_{x}{\mathrm{Ca}}_{0.3}{\mathrm{MnO}}_{3}$ $(0l~xl~0.15)$ have been investigated by ac susceptibility and dc magnetization measurements, including relaxation and aging studies. All investigated samples display a metal-insulator transition. As yttrium is added in the compounds the overall results show evidence for the gradual appearance of a cluster glass behavior. For the $x=0.15$ sample, magnetization measurements as a function of time at various temperatures show that the magnetic relaxation is maximum at a given temperature, well below the ferromagnetic transition. This maximum coincides in temperature with a frequency-dependent feature in the imaginary part of the ac susceptibility, associated with a freezing process. This is interpreted as due to ferromagnetic clusters, which grow with decreasing temperature down to a temperature at which they freeze due to severe intercluster frustration.

Subfields: Condensed Matter Physics, Electronic, Optical and Magnetic Materials

View Paper: https://www.semanticscholar.org/paper/5345fe81291f0f6ca8402428d9f625b9e124fa11