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BELL SYSTEM TECHNICAL JOURNAL 



Table II 

 Measured Temperature Expansions for the Three Crystalographic .\xes 



and evaluating the constants by employing temperatures outside of the 

 ferroelectric range, a normal curve was established. For the X, Y, and Z 

 axes these relations are 



AL 



lO/T, -i-\3 



AL 



= 69.6 X 10""'(r-25) + 7.4 X 10""(T-25)' - 3.13 X 10 "'(T-25) 



{X direction) 



= 43.7 X 10~*(T-25) + 8.16 X 10''(T-25)' - 3.60 X 10~'''(T-25)' 



(I' direction) 



= 49.4 X 10~'(r-25) + 1.555 X 10"'(r-25)' - 2.34 X nr'\T-25) 



{Z direction) 



(i7i; 



