Phase separation in La 0.5 Ca 0.5 MnO 3 doped with 1 % 119 Sn detected by Mössbauer spectroscopy

摘要: $1{%}^{119}\mathrm{Sn}$-doped ${\mathrm{La}}_{0.5}{\mathrm{Ca}}_{0.5}{\mathrm{MnO}}_{3}$ was studied by M\"ossbauer spectroscopy, magnetic moment, and resistivity measurements. The spectra below the charge-ordering temperature are explained with ferromagnetic, antiferromagnetic, ferromagnetic spin cluster components. thermal hystereses of relative intensities components observed in spectra, bulk properties such as moment electrical resistivity, range $125--185 \mathrm{K},$ characteristic phase equilibrium a first-order transition, i.e., separation system transition. component displays significant hyperfine field up to $\ensuremath{\sim}125 \mathrm{K}.$ Above this it exhibits superparamagnetism, becoming dominant above These results discussed framework recent investigations manganite other techniques which also show separation.