Nuclear Resonant Reflectivity Investigations of a Thin Magnetic 57Fe Layer Adjacent to a Superconducting V Layer

With nuclear resonant scattering of synchrotron radiation we have investigated the magnetic hyperfine fields of a thin (∼2 nm) 57Fe layer below and above the superconducting temperature of an adjacent thick (∼50 nm) V cap layer. A standing wave enhancement of the nuclear resonant reflectivity from the buried 57Fe layer was achieved by a periodic superstructure [56Fe/V]25 created below the resonant layer. No visible variation of the magnetization in the 57Fe layer below and above the superconducting transition temperature was observed (neither at the critical angle, nor at the Bragg peak). The strong exchange interaction in the investigated 57Fe layer can explain the result.