ELASTIC PROPERTIES OF AMORPHOUS THIN-FILMS STUDIED USING RAYLEIGH-WAVES

Physical vapor deposition in an ultrahigh vacuum was used to codeposit nickel and zirconium onto quartz single crystals and grow amorphous N i1 -xZrx (0.1 < x < 0.8 7) thin films. A high resolution surface acous tic wave technique was developed for the in situ measurement of the fi lm shear moduli. The modulus has narrow maxima at x = 0.17, 0.22, 0.43 , 0.5, 0.63 and 0.72, reflecting short-range ordering and the formatio n of aggregates in the amorphous phase. It is proposed that the aggreg ates correspond to polytetrahedral atom arrangements which are limited in size by geometrical ''frustration''.