Structure of GaSb digitally doped with Mn

Yamada

2008

Cryst. Res. Technol.

Raman scattering (RS) experiments have been performed for simultaneous determination of Mn composition and strain in Ga 1-x Mn x Sb thin films grown on GaSb substrate by liquid phase epitaxy technique. The Raman spectra obtained from various Ga 1-x Mn x Sb samples show only GaSb-like phonon modes whose frequency positions are found to have Mn compositional dependence. With the combination of epilayer strain model, RS and energy dispersive x-ray (EDX) experiments, the compositional dependence of GaSb-like LO phonon frequency is proposed both in strained and unstrained conditions. The proposed relationships are used to evaluate Mn composition and strain from the Ga 1-x Mn x Sb samples. The results obtained from the RS data are found to be in good agreement with those determined independently by the EDX analysis. Furthermore, the frequency positions of MnSb-like phonon modes are suggested by reduced-mass model.

“…MnSb-like phonon modes It was shown [14] that Mn atom takes Ga site in GaMnSb crystal. If Mn takes the Ga site, then the GaMnSb crystal would follow the Ga 1-x Mn x Sb structure.…”

Section: Resultsmentioning

confidence: 99%

Raman scattering characterization of Mn composition and strain in Ga_1–xMn_x Sb/GaSb epitaxial layers

Mr¹,

Yamada

2008

Cryst. Res. Technol.

“…Since Mn atom takes Ga site in GaSb lattice, the GaMnSb crystal should follow the Ga 1-x Mn x Sb structure [6,17,18]. Raman spectra measured from ternary compound semiconductor Ga 1-x In x As show GaAs-and InAs-like phonon modes [12].…”

Section: B Phonon Mode At 269 CM -1mentioning

confidence: 98%

“…For the last few years, the structural and room temperature ferromagnetic properties have been investigated by x-ray diffraction and vibrating sample magnetometer in this material [4,5]. The structural properties of this material grown by digitally doped Mn are also analyzed theoretically and experimentally using cross-sectional scanning tunneling microscope [6]. There is, however, still not much known about the details of vibrational properties of the Ga 1-x Mn x Sb grown by Mn ion implantation, deposition and post-annealing.…”

Section: Introductionmentioning

confidence: 99%

Vibrational modes in Ga<inf>x</inf>Mn<inf>1−x</inf>Sb studied by Raman spectroscopy

Hasan

Islam

2008 International Conference on Electrical and Computer Engineering

et al. 2008

Raman scattering study on vibrational modes has been reported in ferromagnetic semiconductor Ga 1-x Mn x Sb grown by Mn ions implantation, deposition, and postannealing. The Raman experiments are performed in the implanted and unimplanted regions of the sample before and after etching. Only GaSb-like phonon modes are observed in the spectra measured from the unimplanted region. However, in addition to GaSb-like phonons, some extra modes are observed in the spectra measured from the implanted region of the sample. The experimental results demonstrate that the 115, 152, and 437 cm -1 modes are appeared due to surface defects and crystal disorder caused by Mn ions implantation and deposition processes. The origin of the weak structure observed approximately at 269 cm -1 is not so clear. However, the frequency position of MnSb-like LO phonon mode (266.4 cm -1 ) determined by reduced-mass model is found to be close to the experimentally observed mode at 269 cm -1 . The phonon mode appeared approximately at 659 cm -1 is found to be associated with blackish layer formed on the surface of the sample from the annealing process and is assigned to Mn 3 O 4 -like. Furthermore, existence of coupled LO-phonon plasmon mode is found in the spectra measured from the implanted and close to the implanted regions of the sample.

“…Most of the III-V based DMSs, the ferromagnetic phase transition occurs at maximum Curie temperature of less than 300 K, as reported so far [5,6]. Ga 1-x Mn x Sb on the other hand is an attractive III-V based DMS for fabricating spintronic devices as it shows room temperature ferromagnetic properties [7][8][9]. The magnetic properties in Ga 1-x Mn x Sb arise from the S = 5/2 Mn spin system.…”

Section: Introductionmentioning

confidence: 97%

“…Since Mn acts as an acceptor in Ga 1-x Mn x Sb system, the incorporation of Mn atoms into GaSb lattice sites generate high hole density. It is well established that the maximum Curie temperature of DMSs depends on hole density [6][7][8][9]. Therefore, determination of hole density is very much important for understanding ferromagnetic properties as well as electronic properties of Ga 1-x Mn x Sb material.…”

Section: Introductionmentioning

confidence: 99%

Raman spectroscopic determination of hole density in diluted magnetic semiconductor Ga<inf>x</inf>Mn<inf>1−x</inf>Sb

Hasan

Islam

2008 International Conference on Electrical and Computer Engineering

et al. 2008

Raman scattering determination of hole density has been reported in diluted magnetic semiconductor Ga 1-x Mn x Sb prepared by Mn ions implantation, deposition, and post annealing. The Raman spectra measured from the implanted region of the sample show coupled plasmon LOphonon mode (CPLOM), which is found to be superimposed with GaSb-like phonon modes in the spectra. The spectral lineshapes are modeled using a dielectric function where interband and intraband transitions of free holes are included. In addition to CPLOM, the individual contribution arises from GaSb-like phonon modes are taken into account in the model. The hole density as a function of laser probing position is determined from the best fit parameters and is found to be in reasonable agreement with the results obtained from the electrochemical capacitance-voltage technique. Furthermore, the dependence of optical mobility, depletion width, and peak frequency of CPLOM with hole density is determined.