Magnetic properties of Ga doped NdFeCoB sintered magnets

The magnetic properties of Nd/sub 16/Fe/sub 77/B/sub 7/ and Nd/sub 16/Fe/sub (61-x)/Co/sub 16/Ga/sub x/B/sub 7/ (x=0, 1, 2, 4, 7) have been measured. It was found that the remanent magnetization (B/sub r/), the maximum energy product (BH)/sub max/, and the Curie temperature (T/sub C/) decrease with increasing Ga content. The coercive field (H/sub c/) increases with increasing Ga content when x is smaller than 2, but decreases when x>2. At x=2, the coercive field reaches its maximum value. It was also found in all the samples investigated that there is a linear relationship between H/sub c//sup 1/2/ and T/sup 2/3/, which cannot be explained by Gaunt's wall-barrier model. The temperature dependence of the calculated values of H/sub 0/ and (4bf) is examined.<
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