Molecular Beam Epitaxy of Pd-Fe Graded Magnetic Films for Standing Spin-Waves Control

: The paper demonstrates the capabilities of the molecular beam epitaxy method for deposition of ferromagnetic Pd-Fe alloy thin films with variable composition across the thickness possessing therefore graded magnetic properties. An approach to realize a concentration profile through the temperature control of an effusion cell during the deposition is described in detail. Using this technique, graded ferromagnetic films were synthesized that reveal a possibility to control the spectrum of standing spin waves in them. The limitations of creating graded Pd-Fe films are discussed, associated with the thermal inertia of the effusion cells, as well as with possible phase separation.