Temperature dependence of the hyperfine magnetic field at Fe sites in Ba-Doped BiFeO_(3) thin films studied by emission Mossbauer spectroscopy
Emission Fe-57 Mossbauer spectroscopy (eMS), following the implantation of radioactive Mn-57(+) ions, has been used to study the temperature dependence of the hyperfine magnetic field at Fe sites in Ba-doped BiFeO3 (BFO) thin films. 57Mn fi decays (t(1/ 2) = 90 s) to the 14.4 keV Mossbauer state of...
| Autores: | , , , , , , , , , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/102665 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/102665 |
| Access Level: | acceso abierto |
| Palabra clave: | 538.9 Ba-doped bismuth ferrite Emission Mössbauer spectroscopy Hyperfine magnetic field Néel temperature Magnetoelectric properties Física de materiales Física del estado sólido 2211 Física del Estado Sólido |
| Sumario: | Emission Fe-57 Mossbauer spectroscopy (eMS), following the implantation of radioactive Mn-57(+) ions, has been used to study the temperature dependence of the hyperfine magnetic field at Fe sites in Ba-doped BiFeO3 (BFO) thin films. 57Mn fi decays (t(1/ 2) = 90 s) to the 14.4 keV Mossbauer state of Fe-57, thus allowing online eMS measurements at a selection of sample temperatures during Mn implantation. The eMS measurements were performed on two thin film BFO samples, 88 nm and 300 nm thick, and doped to 15% with Ba ions. The samples were prepared by pulsed laser deposition on SrTiO_3 substrates. X-ray diffraction analyses of the samples showed that the films grew in a tetragonal distorted structure. The Mossbauer spectra of the two films, measured at absorber temperatures in the range 301 K-700 K, comprised a central pair of paramagnetic doublets and a magnetic sextet feature in the wings. The magnetic component was resolved into (i) a component attributed to hyperfine interactions at Fe^(3+) ions located in octahedral sites (B_(hf)); and (ii) to Fe^(3+) ions in implantation induced lattice defects, which were characterized by a distribution of the magnetic field B_(Distr). The hyperfine magnetic field at the Fe probes in the octahedral site has a room temperature value of B_(hf) = 44.5(9) T. At higher sample temperatures, the Bhf becomes much weaker, with the Fe3+ hyperfine magnetic contribution disappearing above 700 K. Simultaneous analysis of the Ba-BFO eMS spectra shows that the variation of the hyperfine field with temperature follows the Brillouin curve for S = 5/2. |
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