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LGEP 2010 ID = 608; International audience; BInGaN quaternary alloys with up to 2% boron and 14% of indium have been grown on GaN/sapphire template substrates by metal-organic vapour phase epitaxy (MOVPE). Epitaxial layer composition was determined by secondary ion mass spectroscopy (SIMS), and confirmed by X-ray photoelectron spectroscopy (XPS). Bandgap energies were measured using optical transmission and reflection spectroscopy. We find that boron incorporation in BInGaN reduces the bandgap, causing an effect similar to the increase of indium content in InGaN. However, adding boron has the advantage of decreasing the lattice mismatch with conventional GaN substrates.

We observed simultaneously two types of Raman spectra in a GaAs/AlGaAs superlattice under high magnetic field: a folded longitudinal acoustic phonon, IFA, and a structureless background, IB. The temperature dependence of the intensities in both spectra was studied in the range 2–100K and it was established that the background spectrum is due to the first-order Raman scattering from acoustic phonons with a wide range of wave vectors. We obtained the expression for the intensities ratio IB/IFA. It depends on the relationship between the homogeneous and the inhomogeneous broadening of the intermediate state of the photoexcited e-h pair. A rapid decrease of IB observed at T 30K is thought to be due to the increase of the homogeneous width with temperature.

Drastic enhancement of the Raman scattering intensity of the folded longitudinal acoustic phonon in a GaAs/AlGaAs superlattice is observed in the presence of a perpendicular magnetic field. A qualitative quasi-classical interpretation of this phenomenon is presented and a dependence of Raman scattering intensity on the magnetic field is obtained.

Electron-beam lithography and wet etching techniques are used to laterally pattern ZnSe/(Zn,Cd,Mn)Se single quantum wells into magnetically active quantum wires with widths ranging from 20 to 80 nm. Photoluminescence spectroscopy as a function of wire width reveals a competition between elastic strain relaxation and quantum confinement. Magnetophotoluminescence measurements at low temperatures indicate a strong exciton spin polarization due to the sp–d exchange-enhanced spin splitting, ranging from 20% to 60% at 4 T.

GaN nanodots and nanostripes with smooth sidewall surfaces have been selectively grown on 6H-SiC substrates by metal organic vapor phase epitaxy. By varying the growth reactor pressure, we have been able to grow either isolated nanostructures or laterally overgrown structures. As confirmed by the Raman scattering and X-ray diffraction techniques, the nanostructures have no influence of step bunching that occurs in the unmasked area of the continuous GaN film. The frequency shift of the E2 optical phonons shows that the residual strain in the nanostripes is relaxed compared to the continuous GaN film. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Intraconnects, as-grown single-walled carbon nanotubes bridging two metal electrodes, were investigated as gated structures. We show that even with a seemingly "ohmic" contact at zero gate voltage one observes negative differential resistance (NDR) at nonzero gate bias. Large differential photo conductance (DPC) was associated with the NDR effect raising hopes for the fabrication of novel high-speed optoelectronic devices.

We report low-temperature (4.2 K) cyclotron resonance measurements on high-mobility, two-dimensional electron gases in modulation-doped ZnSe/Zn1−xCdxSe (x=0.06, 0.12, and 0.24) single quantum wells, as well as in a modulation-doped ZnTe/CdSe single quantum well. These experiments carried out in magnetic fields ranging up to 17 T yield reliable measurements of the effective mass m* of conduction-band electrons in Zn1−xCdxSe alloys, including the measurement of m* in cubic CdSe.

A1. Raman scattering A1. Residual stresses A1. Focus ion beam A1. Stresses A3. Metalorganic vapour phase epitaxy B2. Semiconducting gallium compounds abstract Circular pillar structures of various diameters have been prepared by a focused ion beam (FIB) through a 4-mm-thick epitaxial gallium nitride (GaN) film grown on a sapphire substrate. Micro-Raman scattering is used to measure residual stresses based on the shift of an E2 phonon in the GaN film. Measurements of residual stress profiles are compared to Winkler's elastic formalism for a shear-supported film with proper boundary conditions. The model, optimized at a cleave edge, is compared to the experimental shape of stress variations inside and outside the pillar structures.

Linearly polarized spectra of far-infrared (IR) transmission in ${\text{HoMn}}_{2}{\text{O}}_{5}$ multiferroic single crystals have been studied in the frequency range between 8.5 and $105\text{ }{\text{cm}}^{\ensuremath{-}1}$ and for temperatures between 5 and 300 K. Polarization of IR-active excitations depends on the crystallographic directions in ${\text{HoMn}}_{2}{\text{O}}_{5}$ and is sensitive to the magnetic phase transitions. We attribute some of the infrared-active excitations to electric-dipole transitions between ligand-field (LF) split states of ${\text{Ho}}^{3+}$ ions. For light polarization along crystalline $b$ axis, the oscillator strength of electric dipoles at low frequencies (10.5, 13, and $18\text{ }{\text{cm}}^{\ensuremath{-}1}$) changes significantly at the commensurate-incommensurate antiferromagnetic phase transition at ${T}_{3}=19\text{ }\text{K}$. This effect shows a strong correlation with the pronounced steps of the $b$-directional static dielectric function. We propose that the LF on ${\text{Ho}}^{3+}$ connects the magnetism and dielectric properties of this compound through coupling with the Mn spin structure. We comment on the possibility for composite excitations of magnons and excited LF states.

The intriguing structural properties of a ${\text{ZnMnGaO}}_{4}$ film epitaxially grown on MgO (001) substrate have been investigated using synchrotron-radiation-based x-ray diffraction. The ${\text{ZnMnGaO}}_{4}$ film consisted of a self-assembled checkerboard (CB) structure with highly aligned and regularly spaced vertical nanorods. The lattice parameters of the orthorhombic and rotated tetragonal phases of the CB structure were analyzed by measuring $H\text{\ensuremath{-}}K$, $H\text{\ensuremath{-}}L$, and $K\text{\ensuremath{-}}L$ cross-sectional reciprocal space maps. We demonstrate that symmetry of lattice distortions at the phase boundaries provides means for the coherent coexistence of two domain types within the film volume.

We have observed gate-controlled N-shaped negative differential resistance (NDR) and photoconductivity enhancement in carbon nanotube (CNT) based addressable intra-connects. The intra-connects – bridges spanning across planar electrodes – were measured at room temperature. Individual single-walled CNT (SWCNT) channels were grown using chemical vapor deposition (CVD) precisely between very sharp metal tips on the pre-fabricated electrodes without post-processing. The electrodes were made of cobalt. Methane and H2 gas mixture were introduced into quartz tube for an hour at 900 C, with flow rate of 1900 sccm for methane and 20 sccm for H2. We have investigated two different cases: in one case, the source-drain current-voltage, Ids-Vds, characteristics were linear. The other case exhibited nonlinear Ids-Vds characteristics. Raman scattering of the intra-connects indicated that each were made of SWCNT with radial breathing mode (RBM) at 191.9 cm-1 and 176.2 cm-1, respectively. Current-voltage Ids-Vds characteristics were measured for various Vgs from -10 V to +10 V. Negative differential resistance (NDR) was found in the Ids-Vgs curves for gate bias in the region of -3>Vgs>-6 V. The NDR peak was shifted to the negative side as the source-drain voltage was increased from Vds=0 to 0.75 V. Otherwise, the intra-connects exhibited characteristics of an ordinary p-type channel. The experiments were repeated under white light illumination. The light increases the carrier density in the channel but not in the metal electrodes and allowed us to study the effective doping of the channel without affecting the work function of the SWCNT/metal contact. The overall channel conductance increased under the light irradiation. Under illumination, the devices became more stable, as well. In summary, we have investigated contact properties between a SWCNT intra-connect and metal electrodes in a well controlled layout settings.

We have used a metal–oxide bilayer Raman scattering technique to study lattice dynamics in SrTiO3 thin films. The SrTiO3 thin films were epitaxially grown on a conducting metal–oxide layer which reflects the exciting laser beam so that it does not enter the LaAlO3 substrate. Raman scattering from the SrTiO3 thin films was clearly observed, including the first-order Raman peaks forbidden by the cubic symmetry in single crystals. We suggest that strain exists in the films, which changes the crystal symmetry and will affect the dielectric properties of the SrTiO3 thin films.

Thin films of GaN with the V/III≈10 ratio were grown by low-pressure metal organic vapour phase epitaxy (LP-MOVPE) using N2 and Dimethylhydrazine (DMHy) as a carrier gas and nitrogen precursor, respectively. For the growth temperatures in the range from 550 to 690 ∘C the GaN layers exhibited good surface morphology. In the temperature range from approximately 550 to 610 ∘C, the growth rate increases with increasing temperature, characteristic of the process limited by surface kinetics with the activation energy of approximately 36 kcal/mol. For the temperatures between 620 and 690 ∘C, the growth rate was nearly independent of temperature, which is indicative of a mass transport limited growth. The activation energy was about 4.6 kcal/mol. Micro Raman spectroscopy revealed a significant relaxation of the selection rules for the scattering by the optical phonons in the films grown at lower temperatures. Variation of the intensity ratio for E 2 H and E 1 phonon modes has been attributed to the changes in the structural quality of the films grown at different temperatures.

We measure relative propagation delay between two orthogonally polarized pulses in long fibers in the presence of a weak axial magnetic field (~50μT). We find that the fiber birefringence modifies the Faraday polarization eigenstates, which became noncircular and wander in time.

Optically detected cyclotron resonance of two-dimensional electrons has been studied in nominally undoped CdTe/(Cd,Mn)Te quantum wells. The enhancement of carrier quantum confinement results in an increase of the electron cyclotron mass from 0.099$m_0 $ to 0.112$m_0 $ with well width decreasing from 30 down to 3.6 nm. Model calculations of the electron effective mass have been performed for this material system and good agreement with experimental data is achieved for an electron-phonon coupling constant $\alpha $=0.32.

We study the performance of a commercial bidirectional quantum key distribution system in the presence of a weak magnetic field (about 50 μT) applied along the fiber axis. We observe a quadratic increase in quantum bit error rate with the angle of Faraday rotation. (2 pages)

We study polarization rotations by a dispersion compensation module responding to quasi-periodic room temperature oscillations. The rotations seems to have a functional temperature dependence on short time scales interrupted by rather abrupt shifts occurring, on average, every month. (2 pages)

NRZ and RZ data transmission at 40 Gb/s are demonstrated for the first time using buried heterostructure tandem electro-absorption modulators monolithically integrated with a semiconductor optical amplifier and input/output spot-size converters. Zero penalty RZ transmission over a 100 km dispersion managed link is achieved.

Electro-absorption modulated sources are likely to be key components in the evolution of optical communication line rates from 10Gb/s to 40 Gb/s. Compared with the LiNbO3 alternative EA modulators are more compact, less expensive, compatible with monolithic integration, and offer lower drive voltages. However, fabrication complexity and open questions concerning the fidelity with which they transmit information make the exact role of 40Gb/s EA modulators in advanced communication systems somewhat unclear. In this talk we will describe the design, fabrication and transmission performance of 40Gb/s EA modulators configured for both NRZ and RZ operation. For NRZ transmission the device structure consists of a short MQW modulator with spot-size converters on the input and output ends. Tandem EA modulators for pulse carver and data encoder functions were monolithically integrated along with a semiconductor optical amplifier and input/output spot-size converters to explore RZ transmission. Both single and tandem modulator design are realized using semi-insulting InP current confined buried heterostructure technology. Modulation bandwidth of better than 50 GHz is demonstrated along with a fiber-to-fiber insertion loss of less than 6 dB for the single modulator design. The carver/encoder configuration with onboard SOA yields better than 0 dB insertion loss. Transmission impairments were studies using both designs.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

NRZ and RZ data transmission at 40Gb/s are demonstrated for the first time using buried heterostructure tandem electro-absorption modulators monolithically integrated with a semiconductor optical amplifier and input/output spot-size converters. Zero penalty RZ transmission over a 100km dispersion managed link is achieved.

We report the experimental studies of the vibrational spectra of SrTiO3 films grown by pulsed laser deposition. Raman scattering, with and without bias electric field, and Fourier-transform far-infrared ellipsometry between 30 and 700 cm−1 have been utilized for investigation of the phonon behavior. These results are discussed in connection with the low-frequency dielectric properties of the SrTiO3 films. In the films, the soft mode reveals hardening compared to that in bulk crystals. This observation is in agreement with the Lyddane-Sachs-Teller formalism. The existence of local polar regions is proposed as an important factor determining the dielectric properties of ferroelectric thin films.

The dielectric constant (e) of ferroelectric materials, such as (Ba,Sr)TiO3 (BST) and SrTiO3 (STO), depends strongly on the applied electric field [1, 2]. This phenomenon has been referred to as the dielectric nonlinearity. The dielectric nonlinearity of ferroelectrics has been recognized to be significant for various microwave device applications, because the frequency and phase characteristics of the devices depend on the dielectric constants of both the substrate and the ferroelectric materials in them, and tuning of these characteristics is possible by applying an electric bias to the ferroelectrics [3]. Such tuning is extremely desirable, for example, in high temperature superconductor (HTS) microwave filters, where post-fabrication tuning of bandpass/bandreject frequencies is required. The frequency tuning allows such applications as fast switching of the bandpass and bandreject frequencies to block or transmit different frequencies adoptively, and to change the desired frequency range quickly. Another example is microwave phase shifter, in which the tuning of the dielectric constant changes the lumped circuit capacitance, which in turn affects the amount of the phase shift. An important application of such phase shifters is phased-array antennas which can be electronically steered.

We report on in situ studies of the vibrational properties of ultra-thin Si layers grown by dc magnetron sputtering in ultrahigh vacuum on amorphous MgO and Ag buffer layers. The average thickness of the Si layers ranged from monolayer coverage up to 200 Å. The interference enhanced Raman scattering technique has been used to study changes in the phonon spectra of Si nanoparticles during the crystallization process. Marked size-dependencies in the phonon density of states of the Si quantum dots and the relaxation of the k-vector conservation condition with decrease in size of the Si nanoparticles have been detected. Electron energy loss spectra have been collected for amorphous and crystallized Si nanoparticles on SiO2 buffer layers and the difference in the onset of the electronic transitions have been found.

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Data are presented on in-plane transmission of light and photoluminescence for GaAs/AlAs multiple quantum wells ~MQW’s! uniaxially stressed along the z5@001# growth axis. This stress leads to the simplest possible form of competition between confinement and stress in these microstructures. We show that by measuring the frequency-dependent birefringence in the energy window between the absorption edge of the MQW’s and that of the substrate ~GaAs!, direct information about the competition between uniaxial stress and confinement can be obtained. We find that the inclusion of finite k mixing between heavy- and light-hole bands is necessary in order to account for the otherwise very puzzling polarization rules of the luminescence. The piezobirefringence in the transparency region is found to be of the same order of magnitude than that of bulk GaAs.

Energy relaxation of hot electrons by electron-phonon interaction in 2D structures has received much attention in recent years. Not only the confinement of electrons but also the modification of the phonon spectrum, the appearance of the confined and the interface phonons is of great importance in these structures.

Optical properties of insulating BaSnO3 (BSO) and conducting Ba0.97La0.03SnO3 (BLSO) single crystals were studied at room temperature in a wide spectral range between 0.01 and 5.9 eV by means of spectroscopic ellipsometry. The far-infrared spectra of the optical phonons in BSO and BLSO were complemented by polarized Raman scattering measurements in BSO. The electronic band structure and the optical response (dielectric function) were calculated using density functional theory, which allowed for the interpretation of the main spectroscopic features such as optical phonons and electronic interband transitions. To reconcile the observed experimental spectra with the theory, a departure from the ideal perovskite structure on the local scale was proposed for BSO.

We discovered that perovskite (Ba,La)SnO3 can have excellent carrier mobility even though its band gap is large. The Hall mobility of Ba0.98La0.02SnO3 crystals with the n-type carrier concentration of \sim 8-10\times10 19 cm-3 is found to be \sim 103 cm2 V-1s-1 at room temperature, and the precise measurement of the band gap \Delta of a BaSnO3 crystal shows \Delta=4.05 eV, which is significantly larger than those of other transparent conductive oxides. The high mobility with a wide band gap indicates that (Ba,La)SnO3 is a promising candidate for transparent conductor applications and also epitaxial all-perovskite multilayer devices.

Synchrotron-based x-ray radiation has been utilized to measure time-resolved x-ray excited optical luminescence (TR-XEOL) from InGaN/GaN multiple quantum well (MQW) structures. Excess carrier recombination lifetimes were determined for MQWs grown on conventional c-plane as well as on non-polar m-plane substrates. In addition, the simultaneous measurement of XEOL and x-ray fluorescence reveals an interaction between inner-core excitations of Si impurities and bound exciton recombination in doped GaN-based device structures. Furthermore, the TR-XEOL characterization technique were also applied to InGaN/GaN MQWs grown on GaN inverted pyramid structures.

In this study, we investigated the structural and optical properties of Ge-doped SbTe Ge–ST thin films with three differing compositions: Ge0.06Sb0.77Te0.17 Ge–STH ,G e 0.05Sb0.70Te0.25 Ge–STM, and Ge0.05Sb0.64Te0.31 Ge–STL, grown on Si substrate by radio-frequency sputtering method. The films were annealed at 250°C for crystallization and their crystal structures were examined by X-ray diffraction. Compared to the X-ray diffraction spectra of the undoped SbTe, the Ge–ST thin films had a hexagonal structure with large stacking periods. Using Raman spectroscopy, we investigated the shift of the phonon mode frequencies A1g and Eg of the films with varying Sb:Te ratios. We compared the dependence of the phonon frequencies of Ge–ST on the Sb content to those of the corresponding undoped SbTe. The composition dependence of the A1g phonon frequency could be explained in terms of the linear extrapolation of Sb and Sb2Te3 crystals. By using spectroscopic ellipsometry, we measured the dielectric function of the thin films in the near-IR, visible, and ultraviolet spectral regions. The optical energy gaps and bandgaps of the amorphous and crystalline phases, respectively, were determined using linear extrapolation of the absorption coefficient. The optical gap energies of the amorphous Ge–ST films were determined to be about 0.5–0.6 eV, whereas the indirect bandgap energies of the crystalline films shrank substantially to about 0.15–0.2 eV.

We show that strain, arising from the mismatch between Si and SiO₂ thermal expansion coefficients, directs the thermal crystallization of amorphous Si along Si/SiO₂ interfaces, and produces continuous, fully crystallized nanometer thick Si layers with a lateral-to-vertical aspect ratio close to 100:1. These Si nanolayers exhibit a low density of structural defects and are found to be elastically strained with respect to the crystal Si substrate.

In earlier work we have observed the optical alignment of 2D-electrons in quantum-well structures, which results in the polarization of hot photoluminescence (HPL) [1]. It was emphasized that the peculiarity of the 2D-motion of electrons manifested itself in the strong dependence of the degree of HPL polarization ρ on the energy of the 2D-motion (such a dependence did not exist in the 3D case). Taking into account the quantum confinement of electrons (but not holes) and ignoring the valence band warping, we have obtained an approximate equation which describes the energy dependence of ρ: $$ \rho = \frac{{{{({{{{E_o}}} \left/ {{{E_1}}} \right.})}^2}}}{{8(1 + {{{{E_o}}} \left/ {{{E_1}}} \right.}) + 2{{({{{{E_o}}} \left/ {{{E_1}}} \right.})}^2}}} $$ (1) where Eo is the kinetic energy of the 2D-motion (x,y) of electrons at the point of photocreation and E1 is the confinement energy. In deriving Eq. (1) the z-component of the momentum was put equal to pz = (2mE1)1/2.

In studies of hot electron photoluminescence in multiple quantum well (MQW) structures [1] we have observed an unusual emission close to the excitation line. This luminescence arises in a magnetic field directed perpendicular to the plane of the quantum well. In what follows this luminescence will be called near-resonance luminescence.

We report on the bandgap variation in thin films of BxGa1−xN grown on AlN/sapphire substrates using metal-organic vapor phase epitaxy. Optical transmission, photoluminescence, and x-ray diffraction were utilized to characterize the materials’ properties of the BxGa1−xN films. In contrast to the common expectation for the bandgap variation, which is based on the linear interpolation between the corresponding GaN and BN values, a significant bowing (C=9.2±0.5 eV) of the bandgap was observed. A decrease in the optical bandgap by 150 meV with respect to that of GaN was measured for the increase in the boron composition from 0% to 1.8%.

Synchrotron radiation has been utilized for x-ray diffraction and reciprocal space mapping of InGaN∕GaN multiple-quantum-well (MQW) structures grown on the sidewalls of 10-μm-wide triangular GaN ridges with {1−1.1} facets. Samples were produced by lateral overgrowth through a patterned dielectric mask by using metal-organic vapor-phase epitaxy. Global MQW strain, period, and the tilt of the (00.1) crystallographic planes have been measured across the sidewall facets using a 240nm x-ray beam. Results of this study are interpreted in terms of suppressed intrafacet migration of In and Ga precursors during the MQW growth.

GaN-based 6-μm-wide ridge waveguides with InGaN∕GaN multiple-quantum-wells (MQWs) produced by metal organic vapor-phase epitaxy in the regime of selective-area growth have been studied with microbeam high angular resolution x-ray diffraction and reciprocal-space mapping. Variation of the strain from 0.9% to 1.05% and a factor of 3 for the thickness enhancement of the MQW period have been measured for different widths of the oxide mask surrounding the GaN-based ridges. Only when the trapezoidal shape of the ridge cross section is taken into account can the difference between the experimentally measured thickness enhancement and predictions of the long-range gas-phase diffusion model be reconciled.

Surface migration of the group-III precursors and strain relaxation at the ridge sidewalls are compared for 2.5μm wide waveguides based on InGaAsP and InGaAlAs multiple-quantum-well (MQW) structures. The cross-sectional thickness and strain variations have been measured using synchrotron radiation-based x-ray diffraction with an angular resolution of 2arcs and a beam size of (0.24×0.35)μm2. Indium-rich overgrowth has been observed for the InGaAsP-based waveguides, while InGaAlAs-based waveguides demonstrate thickness uniformity of the MQW active region with a strain relief of 0.4%∕μm at the sidewalls.

Structural and optical properties of the InGaAlAs-based multiple quantum well (MQW) 1.3μm laser structures produced on InP (001) substrates by metal organic vapor phase epitaxy (MOVPE) technique in the regime of selective area growth (SAG) have been studied. An x-ray beam of 10μm diameter generated by a microbeam high-resolution x-ray diffraction (μ-HRXRD) setup based on an imaging one-bounce capillary optic and a three-bounce channel cut Si(004) analyzer crystal has been utilized to measure the diffraction curves from MQW structures grown between oxide mask stripes. The high angular resolution achieved in our experiments allowed accurate measurements of θ–2θ scans over a broad range of angles that was necessary for utilization of fitting algorithms for quantitative analysis of the strain and thickness of individual layers in the MQW structures. The thickness and strain variations in the quantum well and the barrier layers of the MQW SAG structure have been analyzed as a function of the oxide mask width i...

A novel 40 Gbit/s optical receiver is presented. The device consists of a waveguide photodiode integrated with a semiconductor optical amplifier. The receiver has a small signal bandwidth of 39 GHz and a conversion gain of more than 800 V/W. A back-to-back sensitivity of -17 dBm has been demonstrated for non-return to zero data transmission at 40 Gbit/s. A sensitivity of -32dBm or 110 photons/bit has been realised for 40 Gbit/s return to zero transmission with an erbium doped fibre preamplifier and an optical filter.

A linear polarization of the recombination luminescence of photoexcited hot electrons in a multiple quantum well structure has been observed. The peculiarity of electron 2D-motion manifests itself in an observed increase of the polarization with 2D-motion energy. The time of optical-phonon emission by a 2D electron is determined by measuring a magnetic depolarization of the luminescence.

Epitaxial growth of topological insulator bismuth telluride by molecular beam epitaxy onto BaF2 (111) substrates is studied using Bi2Te3 and Te as source materials. By changing the beam flux composition, different stoichiometric phases are obtained, resulting in high quality Bi2Te3 and Bi1Te1 epilayers as shown by Raman spectroscopy and high-resolution X-ray diffraction. From X-ray reciprocal space mapping, the residual strain, as well as size of coherently scattering domains are deduced. The Raman modes for the two different phases are identified and the dielectric functions derived from spectroscopic ellipsometry investigations. Angular resolved photoemission reveals topologically protected surface states of the Bi2Te3 epilayers. Thus, BaF2 is a perfectly suited substrate material for the bismuth telluride compounds.

Effective g factors of electrons and heavy holes in CdTe/CdMgTe quantum wells have been measured with high accuracy as a function of the angle between the magnetic field and the structure growth axis. As a result, we have observed the electron g factor anisotropy in A 2 B 6 -based heterostructures. The dependences of the g factor tensor components on the quantum-well width and the solid solution composition have been calculated within the k · p method and compared with the available experimental data.

We report the experimental studies of the vibrational spectra of SrTiO3 films with the thickness of 1 µm grown by pulsed laser deposition. Fourier-transform infrared ellipsometry between 30 and 700 cm−1 and electric field-induced Raman scattering have been utilized for investigation of the phonon behavior. These results can be used for comparison with the low-frequency measurements of the static dielectric constant. In the films, the soft mode reveals hardening compared to that in bulk crystals. This observation is in agreement with the Lyddane-Sachs-Teller formalism.