X-ray magnetic circular dichroism characterization of GaN/Ga1−xMnxN digital ferromagnetic heterostructure
نویسنده
چکیده
We have investigated the magnetic properties of a GaN/Ga1−xMnxN (x = 0.1) digital ferromagnetic heterostructure (DFH) showing ferromagnetic behavior using soft x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD). The Mn L2,3-edge XAS spectra were similar to those of Ga1−xMnxN random alloy thin films, indicating a substitutional doping of high concentration Mn into GaN. From the XMCD measurements, it was revealed that paramagnetic and ferromagnetic Mn atoms coexisted in the Ga1−xMnxN digital layers. The ferromagnetic moment per Mn atom estimated from XMCD agreed well with that estimated from SQUID measurements. From these results, we conclude that the ferromagnetic behavior of the GaN/Ga1−xMnxN DFH sample arises only from substitutional Mn 2+ ions in the Ga1−xMnxN digital layers and not from ferromagnetic precipitates. Subtle differences were also found from the XMCD spectra between the electronic states of the ferromagnetic and paramagnetic Mn ions.
منابع مشابه
Mn 3d electronic configurations in „Ga1−xMnx...As ferromagnetic semiconductors and their influence on magnetic ordering
We applied x-ray absorption spectroscopy and x-ray magnetic circular dichroism XMCD at the Mn 2p-3d resonances to study the Mn 3d electronic configuration and the coupling of Mn 3d magnetic moments in various Ga1−xMnxAs films. The homogeneity of the Mn depth profile throughout the Ga1−xMnxAs film was tested by additional structure-sensitive x-ray resonant reflectivity measurements. In all inves...
متن کاملMagnetic and optical properties of Ga1−xMnxN grown by metalorganic chemical vapour deposition
Epitaxial layers of Ga1−xMnxN with concentrations of up to x = 0.015 have been grown on c-sapphire substrates by metalorganic chemical vapour deposition. No ferromagnetic second phases were detected via high-resolution x-ray diffraction. Crystalline quality and surface structure were measured by x-ray diffraction and atomic force microscopy, respectively. No significant deterioration in crystal...
متن کاملMagnetic InxGa1 - xN nanowires at room temperature using Cu dopant and annealing
Single-crystal, Cu-doped In x Ga1 - x N nanowires were grown on GaN/Al2O3 substrates via a vapor-liquid-solid (VLS) mechanism using Ni/Au bi-catalysts. The typical diameter of the Cu:In x Ga1 - x N nanowires was 80 to 150 nm, with a typical length of hundreds of micrometers. The as-grown nanowires exhibited diamagnetism. After annealing, the nanowires exhibited ferromagnetism with saturation ma...
متن کاملTitanium dxy ferromagnetism at the LaAlO3/SrTiO3 interface.
A number of recent transport and magnetization studies have shown signs of ferromagnetism in the LaAlO3/SrTiO3 heterostructure, an unexpected property with no bulk analogue in the constituent materials. However, no experiment thus far has provided direct information on the host of the magnetism. Here we report spectroscopic investigations of the magnetism using element-specific techniques, incl...
متن کاملAlloying, co-doping, and annealing effects on the magnetic and optical properties of MOCVD-grown Ga1−xMnxN
Recent theoretical work for Ga1−xMnxN predicts ferromagnetism in this materials system with Curie temperatures above room temperature. Ferromagnetic behavior observed in Ga1−xMnxN is still controversial, as there are conflicting experimental reports owing to the disparity in c
متن کامل