Structural and magnetic properties of FeF2(001)/ZnF2(001) and FeF2(110)/ZnF2(110) superlattices

Using the molecular beam epitaxy technique, fluoride superlattices of FeF2(001)/ZnF2(001) and FeF2(110)/ZnF2(110) were prepared on single-crystal substrates, Al2O3(10(1) over bar 0) and MgO(100), respectively. In addition to structural characterization, dependence of the Neel temperature on the thickness of the FeF2(001) and (110) layers was investigated in detail. The observed periodic variations of the Neel temperature with a period of I atomic monolayer were discussed in terms of an interface-topographical frustration due to the competing exchange interactions of J(2) and J(3).