PREPARATION OF HIGH COERCIVE Sm-Fe-N PERMANENT MAGNET

Using pure Sm and Fe powders as starting materials,high coercive Sm-Fe-N mag-nets have been prepared by mechanical alloying in combination with beat treatmentand nitriding.The best result is:_iH_c=33.1 kA/cm(41.6 kOe)and(BH)_(max)=98.7kJ/cm~3(12.4 MGOe).The phases formed in the specimens during mechanical alloying,crystallizing and nitriding processes were examined by X-ray diffraction technique.Themagnetic properties of the specimens were measured with the pulsed magnetometer infield up to 12 T.Experimental results show that mechanical alloying is an efficient ap-proach for preparing high coercive magnets.As an important factor for obtaining a highcoercivity,the grain sizes of magnets are about tens of nanometer.The presence of somesoft magnetic phases in the specimens leads to a neck on the demagnetization curve.

PREPARATION OF HIGH COERCIVE Sm-Fe-N PERMANENT MAGNET

Using pure Sm and Fe powders as starting materials,high coercive Sm-Fe-N mag- nets have been prepared by mechanical alloying in combination with beat treatment and nitriding.The best result is:_iH_c=33.1 kA/cm(41.6 kOe)and(BH)_(max)=98.7 kJ/cm~3(12.4 MGOe).The phases formed in the specimens during mechanical alloying, crystallizing and nitriding processes were examined by X-ray diffraction technique.The magnetic properties of the specimens were measured with the pulsed magnetometer in field up to 12 T.Experimental results show that mechanical alloying is an efficient ap- proach for preparing high coercive magnets.As an important factor for obtaining a high coercivity,the grain sizes of magnets are about tens of nanometer.The presence of some soft magnetic phases in the specimens leads to a neck on the demagnetization curve.