ZN-67 MOSSBAUER STUDY OF CU-ZN ALLOYS AT HIGH-PRESSURE

The high-resolution 93.3-keV Mössbauer resonance in67Zn was used to investigate Cu-Zn alloys (brass) containing 16.6 wt.% Zn (α-phase) and 50.5 wt.% Zn (β'-phase) at pressures up to 6.2 GPa and at 4.2 K. The recoil-free fraction and the center shift change linearly with reduced volume. The decrease of the center shift is due to the second-order Doppler effect which is partially compensated by the increase of the s-electron density at the67Zn nucleus when the conduction electrons are compressed. In α-brass short-range order leads to four different Cu-Zn configurations. One of them exhibits a center shift which nearly coincides with that of the β'-phase. © 1990 J.C. Baltzer A.G. Scientific Publishing Company.