Magnetic powders and method of making the same

Claim 1

A PROCESS FOR PREPARING MAGNETIC POWER YIELDING MAGNETIC CORES HAVING HIGH RESISTIVITY AND LOW POWER LOSSES WHEN OPERATING AT VERY HIGH FREQUENCIES, WHICH COMPRISES IMPACT MOLLING A MIXTURE OF CARBOYL IRON POWER, DIRECTLY PRODUCED BY THERMAL DECOMPOSITION OF IRON CARBONYL OF WHICH THE WEIGHT AVERAGE PARTICLE DIAMETER IS FROM 2 TO 4 MICRONS AND THE PARTICLE SIZE RANGE IS SUBSTANTIALLY FROM 0.5 TO 5 MICRONS IN DIAMETER, WITH SILICA DUST OF WHICH THE PARTICLES HAVE AN AVERAGE DIAMETER LESS THAN ONE-TENTH OF THE AVERAGE DIAMETER OF THE IRON PARTICLES AND LESS THAN 0.1 MICRON, IN AN AMOUNT FROM 0.2 TO 5% OF THE WEIGHT OF THE IRON POWDER, CONTINUING IMPACT MILLING OF THE MIXTURE UNTIL THE RESULTING POWDER HAS AN APPARENT DENSITY WHEN DRY OF AT LEAST 2.3 GRAMS PER CUBIC CENTIMETER AND SAID SILICA DUST IS UNIFORMLY DISTRIBUTED THROUGHOUT THE MIXTURE, THROUGHLY MIXING THE RESULTING POWDER WITH 0.5 TO 2.5% OF H3PO4 IN SOLUTION IN A VOLATILE ORGANIC SOLVENT, AND EVAPORATING THE SOLVENT.