On the strength of the double exchange and superexchange interactions in La0.67Ca0.33Mn1-yFeyO3 - an NMR and Mössbauer study

Autor:	D. Zając, C.J. Oates, Janusz Przewoźnik, Marcin Sikora, Jan Żukrowski, D. Rybicki, K. Krop, P.C. Riedi, Cz. Kapusta
Rok vydání:	2006
Předmět:	NMR spectra database Magnetization Condensed matter physics Mössbauer effect Ferromagnetism Superexchange Chemistry Mössbauer spectroscopy Analytical chemistry Condensed Matter Physics Hyperfine structure Néel temperature Electronic Optical and Magnetic Materials
Zdroj:	physica status solidi (b). 243:259-262
ISSN:	1521-3951 0370-1972
DOI:	10.1002/pssb.200562425
Popis:	A combined study of La 0.67 Ca 0.33 Mn 0.97 57 Fe 0.03 O 3 compound by means of zero field 55 Mn and 57 Fe NMR as well as 57 Fe Mossbauer spectroscopy (MS) is reported. The 55 Mn NMR spectra exhibit a single double exchange (DE) line up to the magnetic ordering temperature (T C ), 200 K, determined from magnetization measurements. The hyperfine field (HFF) remains finite at the T C , which reveals discontinuous character of the transition and the occurrence of a ferromagnetic-paramagnetic phase segregation. The 57 Fe MS HFF decreases much faster with increasing temperature than the 55 Mn NMR HFF. Application of a molecular field model to the temperature dependence of the 55 Mn and 57 Fe HFF allows to estimate values of the Mn-Mn and the Fe-Mn exchange integrals, which amount to 1.24 meV and -0.6 meV, respectively.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::f1c356c2e42121df51c72c8230f8f6d5 https://doi.org/10.1002/pssb.200562425 Zobrazit plný text záznamu Plný text