磁気光学
MnAl 合金薄膜の磁気および磁気光学特性
1990 年 14 巻 2 号 p. 139-142
詳細
1990 年 14 巻 2 号 p. 139-142
MnAl films prepared in a form of multilayer Mn/Al by vacuum evaporation were investigated. In the Mn content-range of 31∼40 at.%, the films become ferromagnetic (τ-phase) by annealing between 220∼ 420°C. They show the same X-ray diffraction lines of fct(Cu-Au I) structure as bulk MnAl alloy, although the Mn composition range for the τ phase is quite different from that of the bulk; 51-59 at.%. In the films, τ-phase is mixed with a nonmagnetic η-phase below 34 at.% Mn and with a β-phase above 36 at.% Mn. Ms changes with Mn content and shows a maximum of ∼330 emu/cm3 at about 36 at.%Mn. Hc increases from 1 to 6 kOe with increasing Mn content. The θk increases with decreasing wavelength λ and obtains a value of about 0.17° at 400 nm. while the reflectivity R has a value of above 40% in the visible wavelength range.
