98S THE BELL SYSTEM TECHNICAL JOURNAL, OCTOBER 1951 



B 



Assuming that | Zo | » Zt and that Q = "TT > 10, the ratio r which is now a 



real number determines the attenuation A in accordance with equation (13) 

 of the text. 



If the crystal resonance frequency /^ is slightly different from the balance 

 frequency /x obtained with the rod specimen in place, correction may be 

 made by considering a new terminating resistance Zt formed by the crystal 

 driver and a small section of the rod sufficient to make the combined reso- 

 nance equal to /x . A slightly different length, /o, of rod is then used to 

 compulc velocities and attenuation. Also a different mass M tt and ratio r' 

 result. The equation applicable provided /x= Jc , is 



. / iiZ't (/ — cosh Al'n) ..,>. 



smh AIo = -—7 (2:)) 



JxMr 



where 



r — 



1 + 



2f //f-M 

 2(2 v. fJ 



"■-"■['-sd-')] 



^ = '['-|-(|-0] 



In the above a sufficiently accurate value of Q is ordinarily obtained by 

 assuming fe=fx. Further accuracy, if needed, can be obtained by recal- 

 culation, using the corrected value of Q. 



We are glad to acknowledge the cooperation of Mr. J. G. Walker in grow- 

 ing and processing the single crystals used,^ and in preparing also the poly- 

 crystalline specimens. 



References 



1. H. J. McSkimin, //. Aeons. Soc. Anier., 22, 413 (1050), particularly method K. 



2. R. M. Bozorlh, W. P. Mason, H. J. McSkimin, J. G. Walker, PJtys. Rev., 75, 1954 



(1949). 



3. Summarizefl by (a) R. Becker, and W. Dorinp;, Ferromacrnelismus, Springer, Berlin 



(1939), and by (b) R. M. Bozorth, Ferromagnctism, Van Nostrand, New York 

 (1951). 



4. W. P. .Mason, Phyx. Rev. 83, 683 (1951). 



5. H. J. Williams and R. M. Bozorlh, Phys. Rev., 59, 939 (1941), and reference 3b. 



6. H. J. Williams and J. G. Walker, Phys. Rev. 83, 634 (1951). 



