Thermal stability of epitaxial Fe films on GaN(0001)

Abstract

Epitaxial Fe films are grown on GaN(0001) by molecular beam epitaxy at 50 °C. Several samples of one Fe/GaN structure are subjected to rapid thermal annealing from 300 to 950 °C. Using a variety of experimental techniques, we examine the impact of this annealing step upon the morphological, structural, and magnetic properties of these samples. The results demonstrate that the material system Fe/GaN is thermally stable up to a temperature of 700 °C.

Effect of growth temperature on the structural, morphological and magnetic properties of Fe films on GaN(0001)

“…In contrast, Figs. 1(b) and (c) display two distinct reflections 751 relative to GaN ½1 1 2 0 along f. These patterns directly visualize the Pitsch-Schrader OR between Fe and GaN, i.e., a-Feð1 1 0Þ/0 0 1SJGaNð0 0 0 1Þ/1 1 2 0S [1,4,17]. The question arising here is whether or not the width of the reflections in these f RHEED scans actually reflect the in-plane orientation distribution or domain size as obtained by, for instance, EBSD or XRD.…”

“…Figs. 2(c) and (d) show in-plane orientation maps which directly visualize the Pitsch-Schrader OR for these two samples, with the characteristic three symmetryequivalent domains rotated by 1201 relative to each other [1,4]. Evidently, the domain size of the sample grown at 350 1C is much smaller than that of the sample grown at 500 1C.…”

“…Fe offers a high magnetic moment, a Curie temperature well above room temperature, and a sufficiently high spin polarization of 40% [3]. Furthermore, we have recently shown that the Fe/GaN materials system is thermally stable upon ex situ rapid thermal annealing up to temperatures of 700 1C [4] at which GaN itself starts to decompose. This thermodynamic stability may give us the opportunity to synthesize Fe films at temperatures higher than the usually employed % 50 3 C.…”

Structural and magnetic properties of ultra-thin Fe films on metal-organic chemical vapour deposited GaN(0001)

“…Thanks to the predicted 100 ns spin lifetimes at RT 4 and the thermal stability of the Fe/GaN interface up to 750 ºC, 5 the Fe/GaN heterostructure has become a topic of active research. Moreover, development of GaN light-emitting diode has further bolstered the technological importance of GaN devices.…”

Manganese 3×3 and3×3-R30∘str

“…A number of papers have described, for example, the growth of iron on GaN. [1][2][3][4][5] Furthermore, there is great interest in general in the arrangement of atoms and atomic structures formed by depositing different elements onto the GaN(0001) surface. [6][7][8] Despite the high interest in Fe, its reported triple-domain structure on the GaN(0001) surface renders it less than ideal for achieving a homogeneous magnetic thin film on GaN(0001).…”