Mössbauer Spectroscopy applied to materials investigation

• Grant number: 97/07728-5
• Support Opportunities: Research Projects - Thematic Grants
• Start date: May 01, 1998
• End date: July 31, 2001
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Hercílio Rodolfo Rechenberg
• Grantee: Hercílio Rodolfo Rechenberg
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant(s): 99/05513-7 - Mossbauer spectroscopy study of zn-chlorite from canoas deposit, brazil., AR.EXT

Abstract

Our proposal is to use the Mössbauer spectroscopy technique to obtain information of a microscopic character on several kinds of solids. Such information is of a magnetic (hyperfine field), electric (isomer shift, quadrupole interaction) or vibrational (recoil free fraction, 2nd order Doppler shift) nature. The Mössbauer nuclei to be used are 57Fe and 119Sn. Experiments will be carried out at any temperature between 4.2 and 800 K, and in the presence of magnetic fields from 0 to 14 T. Other characterization and measuring techniques, as relevant to each particular problem, will naturally be utilized in addition to Mõssbauer spectroscopy. The following studies are envisaged in this project: a) magnetic properties and hyperf ine interactions in Zr(Fe,Cr)2 laves and their hydrides; b) metamagnetic transitions in R6Fel4-xAlx (R=Nd, La) intermetallic compounds; c) crystallization processes in amorphous metallic alloys and structural characterization of nanocrystalline alloys; d) preparation and characterization of magnetically hard materials based on nitrogenated rare earth-iron alloys; e) magnetic and structural properties of R2BaMO5-type ternary oxides (R=rare earths) and M-Fe-0 ferrites (M =Cu, Zn); f) implementation of I 119Sn Mössbauer spectroscopy and its application to Sn-containing magnetic materials. In addition, we plan to pursue existent collaborations with other research groups, in particular those involving ferromagnetic materials for technological applications, natural or synthetic iron oxides of geological interest, and Fe-containing supramolecular complexes. (AU)