Orthorhombic MnP nanoclusters are formed in GaP epitaxial films grown by metalorganic vapor phase... more Orthorhombic MnP nanoclusters are formed in GaP epitaxial films grown by metalorganic vapor phase epitaxy on GaP(001) substrates, which are labeled as GaP:MnP/GaP(001). Polycrystalline MnP films have also been grown from the vapor phase on GaP substrates and are labeled as ( p-c)MnP/GaP(001). Both GaP:MnP/GaP(001) epilayers and ( p-c)MnP/GaP (001) films show a very rich texture, which has been previously characterized by three dimensional x-ray diffraction reciprocal space maps combined with transmission electron microscopy measurements. Heterostructures (HSs) containing multiple layers of (p-c)MnP/GaP and of GaP:MnP/GaP have been designed and grown with the same process. These HSs add new elements to our understanding of the growth mechanisms involved in these complex systems. In particular, it is shown that Mn diffusion during growth is strongly enhanced leading to a picture of MnP cluster coalescence, which explains some of their properties, such as the variation of their spatial...
Journal of Vacuum Science & Technology A, 2020
Epitaxial to axiotaxial texture transition as a function of substrate temperature is reported in ... more Epitaxial to axiotaxial texture transition as a function of substrate temperature is reported in polycrystalline MnP films, which were grown on GaP (100) substrates using metal organic vapor phase epitaxy. At low growth temperatures, the texture consists of a limited number of epitaxial orientations, which have a common alignment (axiotaxy axis). The number of epitaxial orientations increases at higher growth temperatures, while keeping the same axiotaxy axes, such that only axiotaxial texture is observed at growth temperatures above 700°C. An estimate of the strain values on the axiotaxy axes at the MnP/GaP interface is provided, assuming a periodic interface, which would favor strain minimization as the main reason for the preservation of such a texture. Since MnP grains grow endotaxially on GaP, this texture transition may be a consequence of MnP/GaP interface reconstruction at different growth temperatures.
Recent discovery of graphene and its unique properties has attracted a great deal of interest in ... more Recent discovery of graphene and its unique properties has attracted a great deal of interest in implementing this material in a variety of new devices, targeting applications in ultra-fast electronics, quantum information, carbon-free energy conversion, optoelectronics, and bio-integrated technologies [1,2]. However, graphene lacks a controlled non-zero bandgap, which prevents its large-scale application in electronic and energy conversion devices. To overcome this limitation, we exploit direct integration of III-V semiconductors on graphene through van der Waals epitaxy. Known for their efficient light emission and high charge carrier mobilities, III-V semiconductors are at the core of numerous technologies including high-efficiency solar cells, lasers, light emitting diodes, and ultra-fast transistors, to name a few [3]. Due to lack of dangling bonds on graphene’s surface, in epitaxial growth of III-V semiconductors on graphene the crystals follow the order of graphene lattice th...
We report a simple and fast route to grow ferromagnetic manganese phosphide polycrystalline films... more We report a simple and fast route to grow ferromagnetic manganese phosphide polycrystalline films and nanorods on GaP and on glass substrates using metalorganic vapor phase deposition. Increasing the growth temperature (Z600°C) and growth time (Z30 min) results in nucleation of secondary MnP crystals on the primary grains. The secondary crystals grow faster along a specific direction of orthorhombic MnP (c-axis) and form long rods (up to $ 10 μm) whose diameters are in the nanoscale (20-100 nm). The nanorods can be easily detached from the glass substrate. The films exhibit ferromagnetic behavior with a range of transition temperatures, depending on the growth conditions.
We report on the magneto-optical activity of MnP nanoclusters embedded in GaP epilayers and MnP t... more We report on the magneto-optical activity of MnP nanoclusters embedded in GaP epilayers and MnP thin film as a function of temperature, magnetic field, and wavelength in the near infrared and visible. The measured Faraday rotation originates from the ferromagnetic magnetization of the metallic MnP phase and exhibits a hysteretic behavior as a function of an externally applied magnetic field closely matching that of the magnetization. The Faraday rotation spectrum of MnP shows a magnetoplasmonic resonance whose energy depends on the MnP filling factor and surrounding matrix permittivity. At resonance, the measured rotary power for the epilayer systems increases by a factor of 2 compared to that of the MnP film in terms of degrees of rotation per MnP thickness for an applied magnetic field of 410 mT. We propose an effective medium model, which qualitatively reproduces the Faraday rotation and the magnetocircular dichroism spectra, quantitatively determines the spectral shift induced by variations in the MnP volume fraction, and demonstrates the influence of the shape and orientation distributions of ellipsoidal MnP nanoclusters on the magneto-optical activity and absorption spectra.
van der Waals epitaxy is an attractive alternative to direct heteroepitaxy where the forced Recei... more van der Waals epitaxy is an attractive alternative to direct heteroepitaxy where the forced Received: ((will be filled in by the editorial staff)) Revised: ((will be filled in by the editorial staff))
Orthorhombic MnP nanoclusters are formed in GaP epitaxial films grown by metalorganic vapor phase... more Orthorhombic MnP nanoclusters are formed in GaP epitaxial films grown by metalorganic vapor phase epitaxy on GaP(001) substrates, which are labeled as GaP:MnP/GaP(001). Polycrystalline MnP films have also been grown from the vapor phase on GaP substrates and are labeled as ( p-c)MnP/GaP(001). Both GaP:MnP/GaP(001) epilayers and ( p-c)MnP/GaP (001) films show a very rich texture, which has been previously characterized by three dimensional x-ray diffraction reciprocal space maps combined with transmission electron microscopy measurements. Heterostructures (HSs) containing multiple layers of (p-c)MnP/GaP and of GaP:MnP/GaP have been designed and grown with the same process. These HSs add new elements to our understanding of the growth mechanisms involved in these complex systems. In particular, it is shown that Mn diffusion during growth is strongly enhanced leading to a picture of MnP cluster coalescence, which explains some of their properties, such as the variation of their spatial...
Journal of Vacuum Science & Technology A, 2020
Epitaxial to axiotaxial texture transition as a function of substrate temperature is reported in ... more Epitaxial to axiotaxial texture transition as a function of substrate temperature is reported in polycrystalline MnP films, which were grown on GaP (100) substrates using metal organic vapor phase epitaxy. At low growth temperatures, the texture consists of a limited number of epitaxial orientations, which have a common alignment (axiotaxy axis). The number of epitaxial orientations increases at higher growth temperatures, while keeping the same axiotaxy axes, such that only axiotaxial texture is observed at growth temperatures above 700°C. An estimate of the strain values on the axiotaxy axes at the MnP/GaP interface is provided, assuming a periodic interface, which would favor strain minimization as the main reason for the preservation of such a texture. Since MnP grains grow endotaxially on GaP, this texture transition may be a consequence of MnP/GaP interface reconstruction at different growth temperatures.
Recent discovery of graphene and its unique properties has attracted a great deal of interest in ... more Recent discovery of graphene and its unique properties has attracted a great deal of interest in implementing this material in a variety of new devices, targeting applications in ultra-fast electronics, quantum information, carbon-free energy conversion, optoelectronics, and bio-integrated technologies [1,2]. However, graphene lacks a controlled non-zero bandgap, which prevents its large-scale application in electronic and energy conversion devices. To overcome this limitation, we exploit direct integration of III-V semiconductors on graphene through van der Waals epitaxy. Known for their efficient light emission and high charge carrier mobilities, III-V semiconductors are at the core of numerous technologies including high-efficiency solar cells, lasers, light emitting diodes, and ultra-fast transistors, to name a few [3]. Due to lack of dangling bonds on graphene’s surface, in epitaxial growth of III-V semiconductors on graphene the crystals follow the order of graphene lattice th...
We report a simple and fast route to grow ferromagnetic manganese phosphide polycrystalline films... more We report a simple and fast route to grow ferromagnetic manganese phosphide polycrystalline films and nanorods on GaP and on glass substrates using metalorganic vapor phase deposition. Increasing the growth temperature (Z600°C) and growth time (Z30 min) results in nucleation of secondary MnP crystals on the primary grains. The secondary crystals grow faster along a specific direction of orthorhombic MnP (c-axis) and form long rods (up to $ 10 μm) whose diameters are in the nanoscale (20-100 nm). The nanorods can be easily detached from the glass substrate. The films exhibit ferromagnetic behavior with a range of transition temperatures, depending on the growth conditions.
We report on the magneto-optical activity of MnP nanoclusters embedded in GaP epilayers and MnP t... more We report on the magneto-optical activity of MnP nanoclusters embedded in GaP epilayers and MnP thin film as a function of temperature, magnetic field, and wavelength in the near infrared and visible. The measured Faraday rotation originates from the ferromagnetic magnetization of the metallic MnP phase and exhibits a hysteretic behavior as a function of an externally applied magnetic field closely matching that of the magnetization. The Faraday rotation spectrum of MnP shows a magnetoplasmonic resonance whose energy depends on the MnP filling factor and surrounding matrix permittivity. At resonance, the measured rotary power for the epilayer systems increases by a factor of 2 compared to that of the MnP film in terms of degrees of rotation per MnP thickness for an applied magnetic field of 410 mT. We propose an effective medium model, which qualitatively reproduces the Faraday rotation and the magnetocircular dichroism spectra, quantitatively determines the spectral shift induced by variations in the MnP volume fraction, and demonstrates the influence of the shape and orientation distributions of ellipsoidal MnP nanoclusters on the magneto-optical activity and absorption spectra.
van der Waals epitaxy is an attractive alternative to direct heteroepitaxy where the forced Recei... more van der Waals epitaxy is an attractive alternative to direct heteroepitaxy where the forced Received: ((will be filled in by the editorial staff)) Revised: ((will be filled in by the editorial staff))
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