Synthesis Process and Magnetic Characterization of the Novel Aurivillius Ferroelectric Material ${\hbox{Bi}}_{4}{\hbox{Gd}}_{2}{\hbox{Ti}}_{3}{\hbox{Fe}}_{2}{\hbox{O}}_{18}$

Comprehensive research of the synthesis process by high temperature solid-state reaction method, the crystal structure characterization, and the magnetic properties of the Aurivillius type Bi-layered perovskite-like structure
${\hbox{Bi}}_{4}{\hbox{Gd}}_{2}{\hbox{Ti}}_{3}{\hbox{Fe}}_{2}{\hbox{O}}_{18}$
was undertaken. Patterns of X-ray diffraction measurements and Rietveld analysis allow us to establish that this material crystallizes in a pseudo-orthorhombic structure which belongs to the I2cm (#46) space group. The crystal structure is characterized by
${\hbox{Bi}}_{2}{\hbox{O}}_{2}$
layers and complex perovskite-like structures, with quintuplets octahedra
${\hbox{TiO}}_{6}$
, and the Bi-cations occupying the A-site. The unit-cell parameters are given by
$a=5.5234(2)\ \hbox{\rm{\AA}}$
,
$b=5.5312(2)\ \hbox{\rm{\AA}}$
, and
$c=52.5642(2)\ \hbox{\rm{\AA}}$
, the angles are
$\alpha=\beta=\gamma=90.0^{\circ}$
, and unit-cell volume
${\rm V}=1605.9(1)\ \hbox{\rm{\AA}}^{3}$
. Magnetic properties found from the fit of Curie-Weiss law to the curves of magnetic susceptibility
$\chi$
as a function of temperature show that the Bi-layered Aurivillius material
${\hbox{Bi}}_{4}{\hbox{Gd}}_{2}{\hbox{Ti}}_{3}{\hbox{Fe}}_{2}{\hbox{O}}_{18}$
behaves as a paramagnetic material with evidence of ferromagnetic contributions, and allows for determining the Curie constant, given by
${\rm C}=0.014\ {\hbox{emuK/mol}}$
, effective magnetic moment of
$P_{\rm eff}\mu_{B}=7.78\mu_{\rm B}$
, and temperature independent susceptibility
$\chi_{o}=0.0064\ {\hbox{emu/mol}}$
. Field dependence of magnetization proves strongly paramagnetic behavior of the Bi-layered
${\hbox{Bi}}_{4}{\hbox{Gd}}_{2}{\hbox{Ti}}_{3}{\hbox{Fe}}_{2}{\hbox{O}}_{18}$
.