Temperature dependence of the hyperfine magnetic field at Fe sites in Ba-Doped BiFeO_(3) thin films studied by emission Mossbauer spectroscopy
Loading...
Official URL
Full text at PDC
Publication date
2023
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI
Citations
Exportar
Citation
Abstract
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.
Description
2023 Descuentos MDPI