Magnetic Titanium Pillared Clays (Ti-M-PILCs): Magnetic Studies and Mössbauer Spectroscopy
Bachir, C. / Lan, Y. / Mereacre, V. / Powell, A.K. / Koch, C.B. / Weidler, P.G. (2009)
- place: Clays Clay Min., 57 (2009), 4, 433-443
- Date: 2009
Bachir, C. / Lan, Y. / Mereacre, V. / Powell, A.K. / Koch, C.B. / Weidler, P.G. (2009): „Magnetic Titanium Pillared Clays (Ti-M-PILCs): Magnetic Studies and Mössbauer Spectroscopy“. In: Clays Clay Min., 57 (2009), 4, 433-443
Samples were synthesized at ambient temperature by sodium borohydride reduction of ferrous ions added by ion-exchange to Ti-pillared montmorillonite (Ti-PILCs). The properties of the Ti-M-PILCs were investigated using a superconducting quantum interference device (SQUID) and Mössbauer spectroscopy.
Hysteresis, zero-field-cooled (ZFC), and field-cooled (FC) regimes were measured on different precursor materials prepared by calcination of Ti-PILCs at temperatures between 200 and 600°C. Hysteresis loops, recorded between –7 and 7 T in the temperature range 200–300 K, were observed in most samples depending on the preparation of clays. The ZFC/FC measurements were made after heating from 2 to 300 K under an applied magnetic field of 39.8 kA m–1.
The influence of the calcination temperature of the starting Ti-PILCs on the structural and magnetic properties of the Ti-M-PILCs was examined. The presence of two different Fe-alloy distributions was found; a dispersed one for the less-calcined Ti-PILCs and clusters for the more-calcined ones.