Enhanced Magnetic Softness of Double-Layered Perovskite Manganite La1.7Gd0.3SrMn2O7

Bulk polycrystalline samples of Gd-doped La
_2-x
Gd
_x
La
_2-x
Gd
_x
SrMn
₂
O
₇
SrMn
₂
O
₇
(x = 0.3, 0.6) double-layered perovskite manganites were synthesized in air by conventional solid-state reaction and then annealed at 600 °C in inert (N
₂
) atmosphere. Rietveld refined powder X-ray diffraction patterns show impurity peaks for samples synthesized in air, whereas annealing completely removes the undesired peaks in the lightly doped (15% Gd) sample and partially removes them in the heavily doped (30% Gd) sample. The morphology was improved in both samples due to annealing. Magnetic hysteresis loops demonstrate enhanced magnetic softness for the lightly doped manganite. Its saturation magnetization at room temperature at 10 kOe is 50 emu/g, and is increased to 53 emu/g after heat treatment. Heat treatment also decreases its coercive field and remanent magnetization. These properties indicate that 15% Gd-doped La
_1.7
Gd
_0.3
SrMn
₂
O
₇
manganite may be used in applications where magnetic softness is desired.