Iron clustering in GaSe epilayers grown on GaAs(111)B

Abstract

In this paper we report on the structural, morphological and magnetic properties of semiconducting GaSe epilayers, grown by molecular beam epitaxy, doped to different iron contents (ranging from 1 to 22 at.% Fe). Our results indicate that iron forms metallic Fe nanoparticles with diameters ranging from 1 to 20 nm embedded in the crystalline GaSe matrix. The Fe incorporation proceeds by segregation and agglomeration and induces a progressive disruption of the lamellar GaSe epilayers. The magnetization as a function of the temperature for zero-field cooling with the magnetic field parallel to the surface of the sample provides evidence of superparamagnetic behaviour of the nanoparticles. Cathodoluminescence experiments performed at room temperature reveal semiconducting behaviour even for samples with Fe concentrations as high as 20 at.%.

Cation diffusion and hybridization effects at the Mn-GaSe(0001) reacted interface:Ab initiocalculations and soft x-ray electron spectroscopy studies

“…In the early regime the Mn diffusion through the surface was the dominant mechanism, while in the second regime the segregation of Mn layers on the GaSe surface was the most likely process. Unlike Fe-GaSe interfaces, where iron clustering effects are dominant and no trace of Fe-Se hybridization is found upon the analysis of Fe 2p XPS lineshape 22,23 , our measurements on the electronic properties of the Mn:GaSe interface have shown the capability of Mn to diffuse into the lattice with a remarkable hybridizations with Se anions. Magnetic measurements evidence a paramagnetic behavior for the Mn-doped interface, while the dominant behavior is diamagnetic, due to the bulk of the GaSe host crystal.…”

“…Finally, it is rather important to compare the present results with those obtained on the Fe-GaSe interface 22,23 . The analysis of Fe 2p XPS lineshape in the Fe-GaSe interface does not provide evidence of Fe-Se hybridization, being the Fe 2p XPS spectra quite similar to that of metallic Fe, while Fe clustering effects are found to be dominant.…”

Magnetic Properties of Co0.1Sb2Te3, Ni0.1Bi2Te3 and Ni0.2In4Se3 Compounds

“…The insertion of ferromagnetic elements into layered crystals makes it possible to form a hybrid ferromagnetic-semiconductor nanosystem with matrix insulation of layers. This creates additional opportunities to modify the properties of layered semiconductors, fabricate two-dimensional magnets [5][6][7][8], create new semimagnetic compounds and nanocomposite materials based on semiconductors and ferromagnetic metals [9], etc. In addition, intercalated layered semiconductors are convenient model systems for studying the contributions of the thermodynamic functions of the electronic subsystem of the intercalant in the thermodynamic functions of the layered semiconductor.…”

Preparation of Nanocomposite Magnetic Compounds Based on Layered Semiconductors by Means of Electrochemical Intercalation in a Gradient Magnetic Field

“…One of the approaches for solving this problem consists in the preparation of materials able to combine properties of a ferromagnetic and a semiconductor [1,2]. Because of progress in the technology and methods for preparation of semiconductor materials, along with investigations of single crystals (ferromagnetics and diluted magnetic semiconductors) the growing attention is concentrated on nanocomposite and granular semiconductor systems, films, layered structures and quasi-one-dimensional systems [3][4][5][6][7][8].…”