Studies of magnetization dynamics in sol-gel derived nanocomposites containing transition metal ions and mesoporous templates

Abstract

Nickel and Cobalt ion containing silica based nanoglasses confined within mesoporous SBA-15 and mesoporous alumina templates were synthesized by sol-gel process. These nanocomposites were investigated to understand their microstructure, magnetization dynamics and magnetic memory effects near transition temperatures using state-of-the-art characterization techniques including XRD, TEM and SQUID. The temperature and frequency dependent dielectric properties and Nyquist plot were also investigated. The effect of transition ions and template on memory effect and relaxation dynamics of spin glass phase were explained with Scaling and Vogel-Fulcher laws. The mechanism accountable for the observed characteristics of these nanoconfined amorphous systems are explained systematically. The polarization mechanisms as a function of temperature and frequency were also investigated comprehensively. This study provides an advanced understanding of magnetization dynamics and dielectric property in nanoglass system which will be of fundamental and technological interest that will help to tune and fabricate advanced functional nano materials.