Nano Archive

EPR in functional structures based on doped (nano, meso)-porous silica and titanium dioxide

Kassiba, A and Makowska-Janusik, M and Mehdi, A (2011) EPR in functional structures based on doped (nano, meso)-porous silica and titanium dioxide. Journal of Physics: Conference Series, 289 (1). 012025.

Full text is not hosted in this archive but may be available via the Official URL, or by requesting a copy from the corresponding author.

Official URL: http://stacks.iop.org/1742-6596/289/i=1/a=012025

Abstract

EPR investigations are performed on mesoporous silica (SBA15) functionalized by Nickel-cyclam complexes (1,4,8,11-tetraazacyclotetradecane groups chelating nickel ions) and on mesoporous titanium dioxide with nitrogen doping. For functionalized silica, the magnetic behaviour of organometallic groups, their mutual interactions and dispersion in the host matrices are compared with respect to the doping rates and the synthesis procedures. The relaxation processes were analyzed from the thermal evolution of the paramagnetic spin susceptibilities and EPR line-widths. Particularly, some samples show the formation of clusters where phonon assisted one dimensional (1D) ferromagnetic ordering occurs below 45 K. For the mesoporous TiO 2 , systematic EPR investigations were performed on two main classes of materials with regard to the porosity degrees. The EPR experiments point out the efficiency of EPR method to probe the degree of functionalization of mesoporous silica or the nitrogen doping achievement in TiO 2 , and in general to give a valuable feedback to improve the synthesis routes of smart materials.

Item Type:Article
ID Code:11151
Deposited By:Prof. Alexey Ivanov
Deposited On:01 Nov 2011 23:24
Last Modified:02 Nov 2011 00:47

Repository Staff Only: item control page