Temperature and high-pressure dependent x-ray absorption of SmNiO3 at the Ni K and Sm L3 edges
Wereport on x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine; structure (EXAFS) measurements of SmNiO3 from 20 Kto 600 Kand up to 38 GPa at the NiKand Sm; L3 edges. A multiple component pre-NiKedge tail is understood, originating from 1 s transitions to; 3d-4p states w...
Guardado en:
| Autores principales: | , , , , , |
|---|---|
| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
2015
|
| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/129650 |
| Aporte de: |
| id |
I19-R120-10915-129650 |
|---|---|
| record_format |
dspace |
| institution |
Universidad Nacional de La Plata |
| institution_str |
I-19 |
| repository_str |
R-120 |
| collection |
SEDICI (UNLP) |
| language |
Inglés |
| topic |
Física Química X-ray absorption spectra Hgh-pressure effects in solids Metal–insulator transitions Strongly correlated electron systems |
| spellingShingle |
Física Química X-ray absorption spectra Hgh-pressure effects in solids Metal–insulator transitions Strongly correlated electron systems Massa, Néstor Emilio Ramos, Aline Y. Tolentino, Hélio C. N. Sousa-Neto, Narcizo M. Fonseca, Jairo Alonso, José Antonio Temperature and high-pressure dependent x-ray absorption of SmNiO3 at the Ni K and Sm L3 edges |
| topic_facet |
Física Química X-ray absorption spectra Hgh-pressure effects in solids Metal–insulator transitions Strongly correlated electron systems |
| description |
Wereport on x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine; structure (EXAFS) measurements of SmNiO3 from 20 Kto 600 Kand up to 38 GPa at the NiKand Sm; L3 edges. A multiple component pre-NiKedge tail is understood, originating from 1 s transitions to; 3d-4p states while a post-edge shoulder increases distinctively smoothly, at about the insulator to; metal phase transition (TIM), due to the reduction of electron–phonon interactions as the Ni 3d andO; 2p band overlap triggers the metallic phase. This effect is concomitant with pressure-induced Ni-O-Ni; angle increments toward more symmetric Ni3+ octahedra of the rhombohedral R¯3c space group.; Room temperature pressure-dependent Ni white line peak energies have an abrupt∼3.10±0.04 GPa; valence discontinuity from non-equivalent Ni3+δ + Ni3–δ charge disproportionate net unresolved; absorber turning at∼TIM into Ni3+ of the orthorhombic Pbnm metal oxide phase. At 20 Kthe overall; white line response, still distinctive at TIM∼8.1±0.6 GPa is much smoother due to localization.; Octahedral bond contraction up to 38 GPa and at 300 Kand 20 Kshow breaks in its monotonic; increase at the different structural changes. The SmL3 edge does not show distinctive behaviors either; at 300 Kor 20 Kup to about 35 GPa but the perovskite Smcage, coordinated to eight oxygen atoms,; undergoes strong uneven bond contractions at intermediate pressures where we found the coexistence; of octahedral and rhombohedral superexchange angle distortions.Wefound that the white line; pressure-dependent anomaly may be used as an accurate alternative for delineating pressure–; temperature phase diagrams. |
| format |
Articulo Articulo |
| author |
Massa, Néstor Emilio Ramos, Aline Y. Tolentino, Hélio C. N. Sousa-Neto, Narcizo M. Fonseca, Jairo Alonso, José Antonio |
| author_facet |
Massa, Néstor Emilio Ramos, Aline Y. Tolentino, Hélio C. N. Sousa-Neto, Narcizo M. Fonseca, Jairo Alonso, José Antonio |
| author_sort |
Massa, Néstor Emilio |
| title |
Temperature and high-pressure dependent x-ray absorption of SmNiO3 at the Ni K and Sm L3 edges |
| title_short |
Temperature and high-pressure dependent x-ray absorption of SmNiO3 at the Ni K and Sm L3 edges |
| title_full |
Temperature and high-pressure dependent x-ray absorption of SmNiO3 at the Ni K and Sm L3 edges |
| title_fullStr |
Temperature and high-pressure dependent x-ray absorption of SmNiO3 at the Ni K and Sm L3 edges |
| title_full_unstemmed |
Temperature and high-pressure dependent x-ray absorption of SmNiO3 at the Ni K and Sm L3 edges |
| title_sort |
temperature and high-pressure dependent x-ray absorption of smnio3 at the ni k and sm l3 edges |
| publishDate |
2015 |
| url |
http://sedici.unlp.edu.ar/handle/10915/129650 |
| work_keys_str_mv |
AT massanestoremilio temperatureandhighpressuredependentxrayabsorptionofsmnio3atthenikandsml3edges AT ramosaliney temperatureandhighpressuredependentxrayabsorptionofsmnio3atthenikandsml3edges AT tolentinoheliocn temperatureandhighpressuredependentxrayabsorptionofsmnio3atthenikandsml3edges AT sousanetonarcizom temperatureandhighpressuredependentxrayabsorptionofsmnio3atthenikandsml3edges AT fonsecajairo temperatureandhighpressuredependentxrayabsorptionofsmnio3atthenikandsml3edges AT alonsojoseantonio temperatureandhighpressuredependentxrayabsorptionofsmnio3atthenikandsml3edges |
| bdutipo_str |
Repositorios |
| _version_ |
1764820454681346048 |