ELASTIC STIFFNESS COEFFICIENTS OF SINGLE-CRYSTAL IRON FROM ROOM TEMPERATURE TO 500 DEGREES C

The three adiabatic second-order elastic stiffness coefficients of single-crystal iron are reported from room temperature to 500°C. The coefficients vary in a linear manner with temperature, as opposed to previous results where a departure from linearity took place above 300°C. It seems likely now that this previous behavior was due to the silicone fluid bond between the quartz transducer and the iron specimen, and not the specimen itself. The present work shows that vacuum-evaporated thin-film transducers of zinc sulfide can be used reliably at higher temperatures, in both the longitudinal and transverse modes. However, certain difficulties remain in making transducers to generate all the desired modes for elastic-constant measurements. © 1968 The American Institute of Physics.