An improved, two-parameter distribution method for the description of the Mossbauer spectra of magnetic small particles in an applied field

Autor:	L. H. Bowen, Robert Vandenberghe, R. M. Persoons, E. De Grave, P. M. A. de Bakker
Rok vydání:	1990
Předmět:	Applied Mathematics Magnetic field Computational physics symbols.namesake Nuclear magnetic resonance Ferrimagnetism Lagrange multiplier symbols Antiferromagnetism Distribution method Mossbauer spectra Instrumentation Engineering (miscellaneous) Hyperfine structure Smoothing Mathematics
Zdroj:	Measurement Science and Technology. 1:954-964
ISSN:	1361-6501 0957-0233
DOI:	10.1088/0957-0233/1/9/019
Popis:	An improved method for computer analysis of Mossbauer spectra of small-particle magnetic materials obtained at 4.2 K and in varying external magnetic fields applied parallel to the gamma -ray direction, is presented. The method is based on the simultaneous distribution of the intrinsic hyperfine field Hhf and the canting angle theta between Hhf and the applied magnetic field Hext. The smoothing Lagrange multipliers for both distributed parameters can be chosen independently. The matrix inversion has been solved under the constraint that only positive values are allowed for the resulting probability profile. This matrix inversion is combined with an iteration procedure. The applicability of this model-independent distribution method is illustrated by means of the results obtained for two small-crystallite iron oxyhydroxides, namely ferrimagnetic delta -FeOOH and antiferromagnetic aluminium-substituted goethite ( alpha -AlcFe1-cOOH).
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::8b7275580b77f356cf9ae0b58a5edade https://doi.org/10.1088/0957-0233/1/9/019 Zobrazit plný text záznamu