MAGNETIC PROPERTIES OF PERMINVAR 



31 



ring. The energy losses integrated for complete loops are tabulated 

 in Table I. 



These curves show that the rate of cooling determines the magni- 



B 



600 



400 

 J 

 200 







1000 

 800 

 600 

 400 

 200 

 



4 .8 1.2 1.6 2.0 

 H 



1000 

 800 

 600 

 400 

 200 

 



1600 



1200 



B 800 



400 



5000 



4 .8 1.2 1.6 2.0 24 2.8 4000 



H 



3000 



2000 



1000 



4 .8 1.2 1.6 20 24 2.8 32 3£ 40 

 H 



4 .8 1.2 1.6 2.0 24 2.8 3.2 

 H 



16000 



12000 



1 2 3 4 5 



H 



B 8000 



4000 



16 



20 



24 



Fig. 7— Upper halves of hysteresis loops for Perminvar (45% Ni — 25% Co — 30% Fe) 

 A — air quenched, B — baked at 425° C. 



tudes of the hysteresis losses and the shapes of the hysteresis loops. 

 For the air quenched rings the shapes of the loops for the different 

 flux densities resemble those for ordinary magnetic materials although 

 a few of them show traces of the perminvar characteristics. If a 



