Magnetic Behaviour of Sm₂Co₇/Fe/Sm₂ Co₇, Nanocomposite Trilayers with Cr and Ti Additions

Trilayered Sm₂Co₇/Fe/Sm₂Co₇ spring exchange magnets are fabricated by dc magnetron sputtering on MgO substrates. Very thin layers (0.3-0.7nm) of Cr and Ti are added at the interfaces of the two magnetic phases. The thickness of Sm₂Co₇ is kept at 20nm and Fe at 6nm while the thickness of Cr and Ti are
varied as 0.3, 0.5, and 0.7nm. The base pressure of sputtering chamber is kept below 10^-7Torr and Ar pressure at 3-8mTorr. The samples are haracterized by x-ray diffraction (XRD) and SQUID magnetometer. We report improvement in exchange coupling of nonacomposite magnets by addition of thin layers of Cr at interfaces.