Structure and Magnetic Properties of ${\hbox{Ba}}_{1\hbox{-}{\rm x}}{\hbox{La}}_{\rm x}{\hbox{Fe}}_{12}{\hbox{O}}_{19}$ Prepared by ${\hbox{Ba}}_{1\hbox{-}{\rm x}}{\hbox{La}}_{\rm x}{\hbox{Fe}}_{2}{\hbox{O}}_{4}$

M-type Barium hexaferrite (BaFe
₁₂
O
₁₉
) with substitution of Ba
²⁺
by rare earth metal La
³⁺
were prepared by solid state synthesis method from as-prepared powder of barium monoferrite (Ba
_1-x
La
_x
Fe
₂
O
₄
) (x=0.0, 0.1 and 0.2). The structural and magnetic properties of Ba
_1-x
La
_x
Fe
₁₂
O
₁₉
were investigated by X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and Mössbauer spectroscopy. The refined XRD patterns suggests the formation of single phase hexaferrite. With increased La substitution (x), the saturation magnetization increased and reached maximum at x=0.1 and decreased at x=0.2, without any noticeable change in coercivity. Fitted Mössbauer spectra of Ba
_1-x
La
_x
Fe
₁₂
O
₁₉
showed increase in hyperfine field and a transition from Fe
³⁺
ion to Fe
²⁺
ion at 2b site. The present work demonstrates a new methodology for two stage substitution.