974 



THE BELL SYSTEM TECHNICAL JOURNAL, OCTOBER 1951 



netization. The loss drops from about 7 db to 1 db as the crystal becomes 

 magnetized. The low value is the remanent loss caused by the energy 

 lost to the terminations, so that one can say that the losses due to micro- 

 eddy-current and micro-hysteresis are 6 db per trip or 12.7 db per centimeter 

 for this mode of motion. The Q of the crystal can be shown to be equal to 



400 800 1200 1600 



MAGNETIC FIELD STRENGTH, H,IN OERSTEDS 



2000 



Fig. 3 — Loss per trip (0.472 cm) as a function of magnetizing field for shear wave 

 of Fig. 2. 



the phase shift in radians divided by twice the attenuation in nepers per 

 cm, or 



Q = 



2ir//i> 



2 (rfi per cm)/8.68 



(4) 



and our results give Q = 94, corresponding to a decrement of ir/Q = 0.033. 



Figure 4 shows a measurement of the same mode when the field is applied 



along the [110] direction. The velocity approaches a slightly different 



