Mössbauer Magnetic Scans technique development

G. A. PASQUEVICH; P. MENDOZA ZÉLIS; M. B. FERNÁNDEZ VAN RAAP; A. VEIGA; N. MARTINEZ; F.H.SÁNCHEZ

Rio de Janeiro

Conferencia; X Latin American Conference on the Applications of the Mössbauer Effect; 2006

 In this work the experimental set-up and data analysis procedures for Mössbauer Magnetic Scans (MMS) technique are discussed. The MMS are obtained by measuring the Mössbauer transmission at a fixed Doppler energy as a function of an a.c. external magnetic field. The first work [1] dealing with MMS technique was devoted to the study of 20 mm NANOPERM ribbons. In this previous study the feasibility of the MMS technique was demonstrated for field frequencies between 0.001 and 200 Hz. Although these results suggested that the effect of saturation and polarization absorption phenomena should be taken into account in data analysis, it was clear that the changes in the Mössbauer Transmission were mainly related to the dynamic response of  Fe magnetic moments, and that from these scans the information on magnetic hysteresis mechanisms could be retrieved. In order to determine how the magnetic effect could be deconvoluted from saturation and polarization effects MMS was applied to simpler systems:  a sputtered film with a thickness lower than 1 mm and a 12 mm sheet, both of alpha Fe. To understand how the MMS reflects the magnetic  response of the iron moments in the NANOPERM alloy, a set of Fe90Zr7B3 ribbons preapared in different magnetic nanocrystalline states were analyzed with MMS.