The crystallographic and magnetic properties of Nd _2−x Gd _x Fe ₁₆ Co solid solution and its nitrides

Investigation of (R1−xR′x)2(Fe,Co)17 powders by Mössbauer spectrometry

“…7 where the mean hyperfine field of each samples is reported for the different series. This effect is expected and is due to the fact that the magnetization of the compound increases with the addition of a small amount of Co [15]. This is accompanied by an increase of the Curie temperature, as the Co-Fe exchange interaction is higher than the Fe-Fe exchange interaction.…”

“…We found that the calculated values of the magnetization are very close to the measured saturated magnetization at room temperature [12][13][14][15][16][17] when:…”

“…As the T c value of Sm 2 Fe 17 (399 K [12]) is higher than that of Nd 2 Fe 17 , comparing the Gd 2 Fe 17 , Sm 2 Fe 17 and Nd 2 Fe 17 samples, one can see that the decrease of the mean hyperfine field at room temperature corresponds to the decrease of the T c value. Consistently, the T c values of the Sm 2−x Nd x Fe 17 and Gd 2−x Nd x Fe 17 samples decrease continuously as x increases [12][13][14][15]. Although the lattice parameters a and c increases with the concentration of Nd [12][13][14][15], the increase of T c cannot be explained on the basis of the variation of the unit cell only.…”

“…Consistently, the T c values of the Sm 2−x Nd x Fe 17 and Gd 2−x Nd x Fe 17 samples decrease continuously as x increases [12][13][14][15]. Although the lattice parameters a and c increases with the concentration of Nd [12][13][14][15], the increase of T c cannot be explained on the basis of the variation of the unit cell only. It may be explained by a competition of positive and negative exchange interactions between the Fe atoms.…”

“…In the present paper, the investigations are made by varying the concentration of the rare earths in (R 1−x R x ) 2 Fe 17 and (R 1−x R x ) 2 Fe 16 Co alloys. This study follows previous research on the intrinsic magnetic properties (magnetization and Curie temperature) of the same alloys [12][13][14][15][16][17]. The local information on the Fe sites obtained by Mössbauer spectrometry is compared with previous magnetic data.…”