Published online by Cambridge University Press: 26 February 2011
We prepared Fe/Gd double structured multilayer films (DSMLF's). The Fe/Gd DSMLF has a longer period λl, and it is composed of alternate stacking of two types of Fe/Gd submultilayers with a shorter period λs. One type of Fe/Gd submultilayers has dominant Fe layer magnetization, and the other, dominant Gd layer magnetization. λs was varied in the range from 12 to 100Å, keeping λl to about 250Å. The magnetization of Fe/Gd DSMLF's with λs≦36Å shows a spin-flop in magnetic fields lower than 1k0e at room temperature. The compensation temperature Tcomp was found to decrease with increasing λs. Tcomp crosses room temperature at λs=24Å, and then the spinflop field Hsf at room temperature takes a minimum value of the order of a few tens oersteds. Thus, we show that Hsf at room temperature can easily be tuned to a desired value by varying λs. Longitudinal (pl) and transverse (pt) magnetoresistances show a crossover, depending on the angle between directions of the electric current and of the Fe layer magnetization.