Structural and Magnetic Properties of Gd$_3$(Fe$_1-rm x$Al$_rm x$)$_27.5$Ti$_1.5$

The structural and magnetic properties of Gd
₃
(Fe
_1-x
Al
_x
)
_27.5
Ti
_1.5
(0.1-0.4) have been investigated by X-ray diffraction (XRD), magnetization and Curie temperature (T
_C
) measurements. All the compounds have formed in Nd
₃
(Fe,Ti)
₂₉
(3:29) type structure with Gd(Fe,Ti)
₁₂
(1:12) phase as the secondary phase and traces of alpha-Fe. The unit cell parameters increase anisotropically with the Al content. The saturation magnetization decreases with increasing Al and is attributed to the magneto-volume effect and the modification of the density of states (DOS). The increase of Curie temperature up to x=0.3 and subsequent decrease is explained on the basis of band narrowing. The easy direction of magnetization (EMD) is away from the ab-plane up to x=0.3 changes to along ab-plane for x=0.4