TEM, EPR, Mossbauer studies on nano (CuxBa1-x)(Alx¬Fe¬12 -x)O19

International Conference and Exhibition on Materials Chemistry

March 31-April 01, 2016 Valencia, Spain

S Lakshmi Reddy, T Ravindra Reddy and Tamio Endo

S V D College, India
Mie University, Japan

Posters & Accepted Abstracts: J Material Sci Eng

Abstract :

We report the influence of Cu2+/Al3+ substitution and magnetic properties in the nano particles of ferrite of basic composition CuxBa1-x.(AlxFe12-x)O19 (0.0 �?¢�?�?�?¤ x �?¢�?�?�?¤ 1.0) synthesized by solid-state reaction route method. X-ray diffraction (XRD), transmission electron microscopy (TEM), electron paramagnetic resonance (EPR), Mossbauer, VSM, Fourier transformation infrared (FTIR) spectroscopy techniques, and magnetic measurement are used to investigate the structural and magnetic properties of the synthesized nano particles. XRD results confirm that all the samples are single-phase hexagonal in structure. The unit cell parameters �?¢�?�?�?�?a�?¢�?�?�? and �?¢�?�?�?�?c�?¢�?�?�? are calculated as from 6.276 to 5.777 �?�?�?�? and 23.195 to 23.00 �?�?�?�? respectively with variation of composition from x= 0.00 to 1.00. The average crystallite size of the synthesized nano particles was calculated through Scherrer formula and confirmed by TEM and was found to be 100 nm. FTIR results show the presence of two vibrational bands corresponding to tetrahedral and octahedral sites. EPR spectra are compositional dependent at lower Al/Cu concentration. EPR spectra are due to Fe3+ with x=0 composition and x=1.0 is due to both Fe3+ and Cu2+. EPR results at room temperature reveals that it is ferromagnetic with composition x=0.0 and with x=1.0 it is paramagnetic. Copper is placed in the tetragonal elongation site with magnetically non-equivalent ions in the unit cell. These do not have strong exchange coupling between them. Nonlinear optical properties of the samples indicate that these ferrites are potential candidates for optical limiting applications. Mossbauer studies are suggesting that the sample is ferromagnetic with composition x=0.0 and with x=1.0 super paramagnetic. These results are supported by ESR and VSM studies. Magnetic properties are characterized by vibration sample magnetometer (VSM). All the magnetic properties are found to decrease with the increase in Al�?¢�?�?�?�?Cu content, which is due to the occupation of the doped cations at the octahedral sites (12k and 2a) having spin of electrons in upward direction. In addition, the effects of the substituent agents on these properties of the barium ferrite powders are investigated.

Biography :

Email: drslreddy_in@yahoo.com