MAGNETIC-BEHAVIOR OF FEXNI((1-X)) AND COXNI((1-X)) PSEUDOMORPHIC FILMS ON CU(100)

We set out to compare the ferromagnetic behavior of FexNi(1-x) and Cox Ni((1-x)) films of varying stoichiometry epitaxially grown on Cu(100). The thickness chosen was 5 ML over a wide alloy composition range. Us ing a scaling law for the thickness vs Curie temperature, we extrapola te the bulk fee film thickness and plot the bulk fee Curie temperature as a function of composition. The results suggest (a) that the Invar effect is quenched in these ultrathin pseudomorphic fee films of FexNi (1-x) alloys and (b) the magnetic phase of Fe atoms is the low-spin fe rromagnetic phase. The CoxNi(1-x) films show the expected monotonic de crease in T-c with increasing Ni content. (C) 1996 American Vacuum Soc iety.