TITLE:
Structural, Magnetic, and Electrical Properties of RE Doped Sr0.82RE0.18Fe12-xAlxO19 (RE = Gd, Pr, Sm) Compound
AUTHORS:
Dom Lal Kunwar, Dipesh Neupane, Jiba Nath Dahal, Sanjay R. Mishra
KEYWORDS:
Sr-Ferrite, Nanocomposite, Magnetization, Curie Temperature, Coercivity, Dielectric Constant
JOURNAL NAME:
Advances in Materials Physics and Chemistry,
Vol.9 No.9,
September
19,
2019
ABSTRACT: Among the family of ferrites, M-type hexaferrites
has many industrial applications ranging from simple magnets to microwave
devices. Improvement in magnetic and dielectric properties of ferrites is of
continuous interest. In this present work details study is done to observe the
effect of co-doping of rare-earth (RE3+: Pr3+, Sm3+, and Gd3+)
and aluminum in Sr0.82RE0.18Fe12-xAlxO19 (x = 0.0, 0.5, 1.0, 1.5, 2.0). The adopted samples were synthesized via
autocombustion technique. Detailed synthesis, structural, magnetic, and
electrical measurements of samples were
performed to understand structural-magnetic-electrical property relationship. The Al3+ substitution for Fe3+ brings in a significant enhancement in coercivity but reduces magnetization due
to the magnetic dilution effect. Additional coercivity enhancement was possible
with RE3+ doping without affecting the magnetization of samples.
Among all RE3+ doped samples, Pr3+ doped samples showed the highest Curie temperature, (Tc ~ 465℃), while Gd3+ doped samples showed little variation in dielectric properties in GHz
frequency range. This makes RE3+ doped samples as an ideal candidate
for high-frequency microwave applications. Pr3+ with oblate charge
distribution (negative Stevens constant) was observed to substitute well into
the lattice consequently bringing in desired improvements in physical
properties of Sr0.82RE0.18Fe12-xAlxO19 ferrite.