286 BELL SYSTEM TECHNICAL JOURNAL 



Properties Affected by Magnetization 



In addition to the magnetization, other properties are changed by the 

 direct apphcation of a magnetic field. Some of these, and the amounts by 

 which they may be changed, are as follows: 



Length and volume (magnetostriction) (0.01%) 

 Electrical resistivity (5%) 



Temperature (magnetocaloric effect; heat of hysteresis) (1°C) 

 Elastic constants (20 per cent) 



Rotation of plane of polarization of light (Kerr and Faraday 

 effects) (one degree of arc) 

 In addition to these properties there are others that change with tem- 

 perature because the magnetization itself changes. Thus there is "anoma- 

 lous" temperature-dependence of: 



Specific heat 

 Thermal expansion 

 Electrical resistivity 

 Elastic constants 

 Thermoelectric force 

 and of other properties below the Curie point of a ferromagnetic material, 

 even when no magnetic field is applied. 



Also associated with ferromagnetism are galvanomagnetic, chemical and 

 other effects. 



