TY - JOUR
T1 - Magnetic property enhancement and characterization of nano-structured barium ferrite by mechano-thermal treatment
AU - Molaei, MJ
AU - Ataie, A
AU - Raygan, S
AU - Rahimipour, MR
AU - Picken, SJ
AU - Tichelaar, FD
AU - Legarra, E
PY - 2012
Y1 - 2012
N2 - In this research a mixture of barium ferrite and graphite powders was milled in a planetary ball mill and then heat treated in vacuum to produce BaFe(12)O(19)/Fe(3)O(4) and Fe/Fe(3)O(4) magnetic nano-composites. The effects of milling time and heat treatment temperature on the characteristics of powder mixture were investigated by X-ray diffraction analysis, vibrating sample magnetometer, transmission electron microscopy and Mossbauer spectroscopy. Phase analysis results showed that Fe(2)O(3) in barium ferrite partially reduced to Fe(3)O(4) during milling; hence, the reduced phase and remaining barium ferrite formed a nano-composite of BaFe(12)O(19)/Fe(3)O(4) after 20 h of milling. Heat treatment of the 40 h milled samples at 750-900 degrees C resulted in formation of Fe containing nano-composite. Magnetic measurements indicated that the coercivity of 267.92 Oe for 40 h milled sample decreased to 22.57 Oe by heat treatment at 900 degrees C, while its saturation magnetization increased from 31.56 to 169.43 emu/g due to the formation of Fe nano-crystallites.
AB - In this research a mixture of barium ferrite and graphite powders was milled in a planetary ball mill and then heat treated in vacuum to produce BaFe(12)O(19)/Fe(3)O(4) and Fe/Fe(3)O(4) magnetic nano-composites. The effects of milling time and heat treatment temperature on the characteristics of powder mixture were investigated by X-ray diffraction analysis, vibrating sample magnetometer, transmission electron microscopy and Mossbauer spectroscopy. Phase analysis results showed that Fe(2)O(3) in barium ferrite partially reduced to Fe(3)O(4) during milling; hence, the reduced phase and remaining barium ferrite formed a nano-composite of BaFe(12)O(19)/Fe(3)O(4) after 20 h of milling. Heat treatment of the 40 h milled samples at 750-900 degrees C resulted in formation of Fe containing nano-composite. Magnetic measurements indicated that the coercivity of 267.92 Oe for 40 h milled sample decreased to 22.57 Oe by heat treatment at 900 degrees C, while its saturation magnetization increased from 31.56 to 169.43 emu/g due to the formation of Fe nano-crystallites.
U2 - 10.1016/j.matchar.2011.11.004
DO - 10.1016/j.matchar.2011.11.004
M3 - Article
SN - 1044-5803
VL - 63
SP - 83
EP - 89
JO - Materials Characterization
JF - Materials Characterization
ER -