Longitudinal spin-density-wave ordering in thin epitaxial chromium layers

Thin chromium films molecular beam epitaxy grown on partly relaxed MgO/Fe s ubstrates held below T = 150 degrees C are found either nonmagnetic below a chromium thickness around 5.0 nm or in a single-Q magnetic domain with the longitudinal (spins-out-of-plane) spin-density-wave (SDW) ordering stable up to 500 K. The longitudinal SDW-to-paramagnetic transition, the absence o f the spin-flip transition and the actual character of the SDW depends on s pecific growth conditions. The present results reveal the spin-flip transit ion in chromium as an anisotropy effect rather than an intrinsic feature of the SDW ordering. (C) 1999 American Institute of Physics. [S0021-8979(99)5 8808-7].