Authors : 1A. D. Deshpande; 2V. M. Nanoti, 3K. G. Rewatkar
Page Nos : 290-297
Description :
Powders of calcium hexaferrites doped with Zirconium - Cobalt CaFe11(ZrCo)O19 and
CaFe10(ZrCo)2O19 have been synthesized. The nitrates are used as oxidants accompanied
with urea as a fuel. Conventional Sol-gel technique is improved by replacing
conventional heating furnace by a microwave source, hence the method is named as
‘The Microwave Induced sol-gel combustion route’ [1,2]. Structural analysis of the
synthesized powders have been carried out using X-ray diffraction spectroscopy (XRD)&
Morhological study is done using Transmission electron microscopy (TEM). Values of
Lattice parameters (a, c) confirms the formation of Hexaferrite unit cell [3]. TEM imaging
demonstrate the formation of nanosize particles. Variatoin of loss tangent (tan ) is
studied as a function of frequency using precision impendence Analyser. Value of DC
electrical resistivity (ρ) is also determined for the samples. Response to the external
applied magnetic field is studied using Vibrating sample magnetometer (VSM), which
show the moderate values of saturation magnetization (Ms), Remenace (Mr) and
Coercivity (Hc). These nano sized materials with high resistivity are reported to be
useful specially for the many Microwave absorbing applications. Also the reduction of
particle size of hexaferrites to nanorange helps to improve magnetic and electric
properties mentioned earlier.
