Physics NotePublished
Studies of System
M. A. M. Jacome; E. M. B. Saitovitch; S.G. García
1992
Publication details
- Authors
- M. A. M. Jacome; E. M. B. Saitovitch; S.G. García
- Type
- Physics Note
- Status
- Published
- Publication date
- 1992
- Description
- The increase of Gd concentration induces a structural phase transition in the <math>(La_{1-x}Gd_x)\,\!</math><math>_{1.85}Sr_{0.15} CuO_4\,\!</math> system, going through the <math>T, T^*\,\!</math> and <math>T'\,\!</math>-phases, for which <math>Cu\,\!</math> has octahedral, pyramidal and planar oxygen coordinations, respectively. Samples with <math>x = 0.0, 0.35, 0.45, 0.75\,\!</math> and <math>1.0\,\!</math>, substituting <math>1\,\!</math> at <math>%\,\!</math> of Cu by <math>^{57}Fe\,\!</math> , were studied at room temperature by Mössbauer spectroscopy and x-ray diffraction measurements. Five different quadrupole doublets were needed to fit the Mössbauer spectra for all the samples of the system. The isomer shifts (IS) values corresponds to <math>Fe^{3+}\,\!</math> ions, except for two contributions of the <math>x = 1.0\,\!</math> sample (<math>T'\,\!</math>-phase), showing a sharp reduction. The systematics of all the results for the system as a whole allows an interpretation of the different contributions to the Mössbauer spectra in terms of local oxygen surroundings.
- Year
- 1992
- Number
- CBPF-NF-042/92
- Linked to a thesis
- No
- Linked to a grant
- No