254 



BELL SYSTEM TECS MICA L JOURNAL 



tion. 



4 0,8 1.2 1.6 20 24 2.8 3.2 3 6 4 4.4 4.8 5.2 5 6 6.0 6.4 6 8 



-Ic IN MILLIAMPERES 



Fig. 7 — Collector characteristic Y c vs /« for fixed /, but variable distance of separa 



0.005 



0.025 



0.010 0.015 0.020 



SEPARATION IN CENTIMETERS 



Fig. 8 — Emitter current /« vs separation for fixed Ic and V c 



0.030 



different surface which was ground Hat, etched, and then oxidized at 500°C 

 in moist air for one hour. The resultant oxide film was washed off.^'' The 

 emitter current /« was kept constant at 1.0 ma. 



