Experimental design and Methodology for a new

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

Kanpur, India

Conferencia; International Conference on the Applications of the Mössbauer Effect; 2007

A new experimental setup and methodology which allows the automatic tracking of a Mössbauer absorption line as its energy position varies during the experiment is introduced. The experimental setup uses a conventional pulse height selection branch, a conventional Mössbauer driving system, and a novel programmable constant-velocity scaler replacing the usual multiscaler. This layout allows the acquisition of partial spectra in energy regions of interest (ROI) using a constant velocity strategy. It can be fully operated by a remote application and data acquisition can be automated. The ROI is shifted using a versatile and modifiable algorithm hosted in a PC. In this way, an absorption line position can be tracked as a function of an external parameter (temperature, pressure, magnetic field, degree of a solid state reaction advance, etc.) and the evolution of a quantity of interest can be measured (e.g. presented here: the dependence of Bhf on T in FeSn2 ). Preliminary tests were performed on simulated experiments. As an experimental test the temperature dependence of the 57Fe hyperfine field in FeSn2 was determined. To this end the temperature evolutions of the fifth and sixth spectral lines of FeSn2 between RT and a temperature slightly above its Nèel temperature (383 ºK) were tracked.