ELASTIC CONSTANTS AND LOSSES EST NICKEL 989 



7. J. G. Walker, H. J. Williams and R. M. Bozorth, Rev. Set. Instruments, 20, 947 (1949) 



and reference 2. 



8. W. P. Mason, P/tys. Rev. 82, 715, (1951). 



9. W. P. Mason, Piezoelectric Crystals and Their Application to Ultrasonics, Van 



Nostrand, New York (1950). 



10. K. Honda and Y. Shirakawa, Nippon Kinzoku Gakkai-Si (//. Inst. Metals, Japan) 



;, 217 (1937), and Sci. Re/). Res. Insl., Tohoku Univ. J, 9 (1949). 



11. M. Yamamoto, //. Inst. Melds, Japan 6, 331 (1942) and P/iys. Rev., 77, 566 (1950). 



12. This method is a modification of one described in "Electromechanical Transducers 



and Wave Filters," W. P. Mason, D. Van Nostrand (1942) pages 244-247. For 

 frequencies above 20 kc, 45° Z-cut ammonium dihydrogen phosphate crystals were 

 used. Below 20 kc the crystals were cemented on square brass rods which were 

 placed at the ends of the nickel rods in place of the piezoelectric crystals alone. 



13. W. Doring, Z. Pliysik, 114, 579 (1939). 



