Magnetic properties of single-crystal {110} iron films grown on GaAs by molecular beam epitaxy (invited)

Abstract

Single-crystal {110} Fe films, grown for the first time by molecular beam epitaxy on GaAs, have been studied by a variety of techniques in order to determine the dependence of the magnetic properties upon film thickness L and quality, and an overview of these results is presented. The dependence of the ferromagnetic resonance (FMR) field upon its orientation in the (11̄0) plane was measured at 16.4 GHz and shows that the magnetically easy axis is [110] for L<50 Å and [001] for L≳150 Å. A theory of FMR which incorporates magnetocrystalline surface anisotropy is outlined. It successfully interprets the thickness dependence of the FMR data in the ultrathin (L≲50 Å) regime and shows them to be surface dominated. FMR data at 9.2 GHz, which contain both aligned and nonaligned resonance branches, are presented as a function L. In addition, the dependence of the branches on frequency f for 8 GHz<f<40 GHz along [001] and [110] are discussed.

Magnetic properties of Nd/Fe double layers grown on Si(111) by electron beam evaporation

“…In particular, the value 2K 1 /M ϭ0.30 kOe obtained for the uncovered Fe͑60 Å͒ layer is very close to the value 0.34 kOe measured for Fe͑50 Å͒/Si͑111͒. 10 The observed linewidth for the Fe͑60 Å͒ film was approximately 37 Oe, close to the best values observed for Fe and other transition metal films, 14,15 indicating the good crystallinity of the samples. Figure 2 shows the variation of the linewidth versus in-plane angle for Nd͑10 Å͒/Fe͑100 Å͒/ Si͑111͒.…”

Structural and Magnetic Properties of Co<SUB>2</SUB>FeAl<SUB>0.5</SUB>Si<SUB>0.5</SUB> Full-Heusler Alloy Thin Films on GaAs Substrates

“…5(b), M r ½1 1 10=M r ½110 decreases by reducing the CFAS thickness except the CFAS thin films deposited at T SUB ¼ 400 C. This tendency except the CFAS thin films deposited at T SUB ¼ 400 C indicates that these magnetic anisotropy derived from CFAS/GaAs interface. Such magnetic anisotropy in ferromagnets on GaAs has been reported, 14,16,17) however, the mechanism of that is not clear now. Additionally, the CFAS on MgO-buffered CFAS has also shown such magnetic anisotropy, however, the enough high spin polarization has been observed with that.…”

“…13,14) Since, the purpose of this study is to clarify the structural and magnetic properties of CFAS thin films grown on GaAs (001) substrate. In addition, the ferromagnets thin films on GaAs substrates showed the magnetic anisotropy 14,16,17) and the mechanism of this magnetic anisotropy has not cleared yet. Hence, we will discuss the mechanism of this magnetic anisotropy also.…”

Continuous evolution of the in-plane magnetic anisotropies with thickness in epitaxial Fe films

“…Magnetic anisotropies of oxidized or Al-coated Fe films deposited on either GaAs͑001͒ or ͑110͒ were investigated by Prinz and co-workers using ex situ techniques such as ferromagnetic resonance ͑FMR͒ and vibrating sample magnetometry ͑VSM͒. 11,12 The magnetization reversal process in Fe/ GaAs͑001͒ films was studied using the magneto-optic Kerr effect ͑MOKE͒. 13,14 No evidence for dominating perpendicular anisotropy was found when studying the extraordinary Hall effect in Fe/GaAs films.…”