1364 THE BELL SYSTEM TECHNICAL JOURNAL, NOVEMBER 1953 



dielectric loss is particularly striking, indicating that the primary mech- 

 hanism of loss in these ferrites is simply ohmic conductivity loss. This 

 series of measurements clearly shows that the presence of even a very 

 small amount of divalent iron is undesirable in ferrites to be used at 

 microwave frequen<jies. 



TRANSVERSE FIELD MEASUREMENTS 



Two classes of measurements are commonly made in which a transverse 

 dc magnetic field is applied parallel to the electric vector of the TEoi 

 mode in rectangular waveguide. Those measurements involving a com- 

 pletely filled or symetrically loaded waveguide yield primarily recipro- 

 cal effects which are useful in applications as previously mentioned. 

 More useful, still, are the non-reciprocal effects observed when a piece 

 of ferrite is placed asymetrically in a waveguide and transversely mag- 



-0.01 0.01 0.02 0.03 



IRON EXCESS OR DEFICIENCY IN ATOMS PER MOLECULE 



Fio. 19 — Factor of merit versus iron content of NiZn ferrite. 



