Evidence for superparamagnetism within a molecular sieve: Magnetic and Mössbauer effect studies

Abstract

A novel method for dispersing iron inside a silicate matrix, more specifically molecular sieve 13X, has been developed. This has obvious advantages over iron dispersions on external surfaces, as in catalysts, thin films, etc. The transition from paramagnetism to superparamagnetism to antiferromagnetism has been studied in this zeolite system (molecular sieve 13X) into which Fe3+has been introduced. Both Fe(CO) 5 and FeCl 3 have been used to obtain Fe 2 O 3 under certain conditions as described. Magnetic susceptibility, Mossbauer spectroscopy, X-ray diffraction, and electron microscopy have been used to elucidate the resulting products.