PRODUCTION METHOD FOR PHOSPHATE-COATED SmFeN-BASED ANISOTROPIC MAGNETIC POWDER, AND BONDED MAGNET

A bonded magnet comprising

• polypropylene;
• and
• a phosphate-coated SmFeN-based anisotropic magnetic powder having a content of a phosphate greater than 0.5 mass %,
• wherein a retention rate of a total flux after a test of immersing the bonded magnet in 120° C. hot water and maintaining the state thereof for 1000 hours is 95% or greater relative to a total flux before the test.

A phosphate-coated SmFeN-based anisotropic magnetic powder, wherein

• a content of a phosphate is greater than 0.5 mass %,
• a phosphate coating present on a surface of an SmFeN-based anisotropic magnetic powder comprises a first region and a second region, and an Sm atomic concentration in the first region is higher than an Sm atom concentration in the SmFeN-based anisotropic magnetic powder,
• the Sm atomic concentration of the first region is in a range from 0.5 times to 4 times an Fe atomic concentration in the first region, and
• the second region is present on the first region, and an Sm atomic concentration of the second region is not more than ⅓ times an Fe atomic concentration in the second region.