482 



BELL SYSTEM TECHNICAL JOURNAL 



by Pearson is shown in Fig. 5. Two probe points were placed about 

 .009 cm apart near one end of a germanium filament. The concentration 



HOLES INJECTED 



POTENTIAL DIFFERENCE AND 

 CONDUCTANCE MEASURED 



Y'\g. 5.- — Experimental arrangement used by G. L. Pearson to investigate relation be- 

 tween admittance and hole concentration in germanium filament. 



0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 



HOLE DENSITY IN TERMS OF p/n^ 



I''ig. 6. — The relalionshii) i)elween jioint admittance and relative hole concentration, 

 for a germanium lilamcnl from (1. L. Pearson's data of Septcml)cr 28, 1948. 



of holes was varied by current from an emitter point near tiie opposite 

 end of tiie filament. There was an additional current flowing between 



