FACTORS AFFECTING MAGNETIC QUALITY 



285 



will show here the effect of the thickness of electrodeposited films of cobalt. 

 Magnetization curves are shown in Fig. 37 according to previously un- 

 published work of the author. 



I 10 



I 



CD 







10 



20 



30 



100 



110 



120 130 



40 50 60 70 80 90 

 FIELD STRENGTH, H, IN OERSTEDS 



Fig. 37 — Dependence of the magnetization curves of pure electrodeposited cobalt films 

 on the thickness. 



10^x12 



, 6 



• 20 40 60 80 



PARTICLE DIAMETER IN MICRONS 



(l MICRON = lO"'* cm) 



Fig. 38 — Dependence of coercive force on the particle size of MnBi powder. Giiillaitd. 



'J'he high coercive force obtained in fine powders by GuillaucU^ is one of 

 the most clear cut e.xamples of the intrinsic effect of particle size. The coer- 

 cive force increases by a factor of 15 as the size decreases to 5 X 10~'* cm 

 (Fig. 38). 



i«C. Guillaud, Thesis, Strasbourg (1943). 



