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Showing papers on "Antimonide published in 2002"


Journal ArticleDOI
TL;DR: Using these devices an experimental setup for open path gas detection has been developed and their emission wavelength makes them suitable for the detection of many gas species in the wavelength range which corresponds to an atmospheric transmission window.

90 citations


Journal ArticleDOI
TL;DR: The binary antimonide Mo3Sb7 is metallic with poor thermoelectric properties and has been investigated in this article, showing that substitution of Te atoms can replace up to 2.3 Sb atoms without noticeable structural changes, leading to a dramatic enhancement in the thermopower.
Abstract: The binary antimonide Mo3Sb7 is metallic with poor thermoelectric properties. Since band structure calculations indicated a possible change to semiconducting behavior by adding two more valence-electrons, the substitutional series Mo3Sb7 − δTeδ has been investigated. Te atoms can replace up to 2.3 Sb atoms in Mo3Sb7 without noticeable structural changes. This substitution leads to a dramatic enhancement in the thermopower, indicating that in fact semiconducting properties have been achieved with the synthesis of Mo3Sb5Te2.

83 citations


Journal ArticleDOI
TL;DR: In this article, small-area antimonide-based backward diodes for zero-bias millimeter-wave detection have been fabricated using high-resolution I-line stepper lithography, allowing accurate control of the small device active area required for operation at W-band.
Abstract: Small-area antimonide-based backward diodes for zero-bias millimeter-wave detection have been fabricated and tested. The devices were fabricated using high-resolution I-line stepper lithography, allowing accurate control of the small device active area required for operation at W-band. The devices exhibit excellent measured performance from 1-110 GHz, with responsivities when driven from a 50-/spl Omega/ source of 2540 V/W at 95 GHz. This translates to a projected responsivity of 11.5 /spl times/ 10/sup 3/ V/W at 95 GHz for a conjugately matched detector. The compression characteristics of the detectors have been measured, with 1.2 dB of responsivity compression for an input power of 8 /spl mu/W.

56 citations


Journal ArticleDOI
TL;DR: Measurements of atmospheric carbon dioxide with a room-temperature 2 microm indium-phosphide laser, applications of antimonide lasers for methane and formaldehyde sensing in the 3-4 microm range and a fast chemical sensor for methane flux measurements based on lead-salt diode-lasers operating near 7.8 microm will be presented.

38 citations


Journal ArticleDOI
TL;DR: In this paper, the two isotypic compounds Ni5.66SbTe2 (Ni5.72SbSe2) have been synthesized by high-temperature reaction of the elements or by using a flux method.
Abstract: The two isotypic compounds Ni5.66SbTe2 and Ni5.72SbSe2 have been synthesized by high-temperature reaction of the elements or by using a flux method. They were both characterized by single-crystal X-ray diffraction. Both compounds crystallize in space group I4/mmm with Z = 2. Ni5.66SbTe2 (Ni5.72SbSe2) has lattice parameters a = b = 3.7824(5) A and c = 19.244(4) A (a = b = 3.7021(5) A and c = 18.593(3) A). There is a high concentration of nickel vacancies (≈66%) on one of the three nickel sites (Wyckoff position 4e). Thermopower, thermal conductivity, resistivity, and magnetic susceptibility data for Ni5.66SbTe2 indicate nonmagnetic and metallic behavior.

28 citations


Journal ArticleDOI
TL;DR: In this article, the ternary antimonides YbTSb (T= Ni, Pd, Pt, Cu, Ag, Au) were synthesized by reaction of the elements in sealed tantalum tubes in a high-frequency furnace.
Abstract: The ternary antimonides YbTSb (T= Ni, Pd, Pt, Cu, Ag, Au) were synthesized by reaction of the elements in sealed tantalum tubes in a high-frequency furnace. The structures of YbCuSb (NdPtSb type), YbAgSb (TiNiSi type), and YbAuSb (NdPtSb type) were confirmed on the basis of X-ray powder diffraction data. Those of the nickel, palladium, and platinum based antimonides (cubic MgAgAs type) were refined from single crystal X-ray data. The nickel based antimonide has a pronounced homogeneity range YbNi x Sb. The structures of five crystals have been investigated. The cubic lattice parameter increases with increasing nickel content from 613.13(6) pm (x = 0.17) to 621.25(5) pm (x = 0.63). Full occupancy of the palladium and antimony sites was observed for YbPdSb while the platinum compound shows some platinum vacancies leading to the composition YbPt 0 . 9 6 9 ( 7 ) Sb for the investigated crystal. A new, high-temperature modification of YbPdSb was obtained by rapidly quenching an arc-melted sample: TiNiSi type, Pnma, a = 725.6(2), b = 458.3(1), c = 785.4(2) pm, wR2 = 0.1255, 421 F 2 values, 20 variables. The antimonides YbTSb (T= Ni, Pd, Pt, Cu, Ag, Au) show single 1 2 1 Sb Mossbauer signals at isomer shifts ranging from -7.34 to -7.82 mm/s. The crystal chemistry and chemical bonding of these antimonides is discussed.

24 citations


Patent
30 Sep 2002
TL;DR: Bulk Aluminum Antimonide (AlSb)-based single crystal materials have been prepared for use as ambient (room) temperature X-ray and Gamma-ray radiation detection.
Abstract: Bulk Aluminum Antimonide (AlSb)-based single crystal materials have been prepared for use as ambient (room) temperature X-ray and Gamma-ray radiation detection.

12 citations


Proceedings ArticleDOI
07 Aug 2002
TL;DR: In this paper, the authors consider the implications of a staggered "type-II" band line up for InAs/AlSb quantum well HFETs, PnP AlSb/InAs/Sb double heterojunction bipolar transistors (DHBTs), and InP/GaAsSb /InP NpN DHBTs.
Abstract: Antimony containing III-V compounds have long been considered to be promising for high-speed applications at millimeter wave frequencies. Part of their attractiveness comes from the flexibility in heterostructure design afforded by the addition of antimony to arsenic and/or phosphorus containing compounds. A central design feature of antimonide heterostructures is the presence of a staggered "type-II" band line up, and we consider the implications of this special lineup for InAs/AlSb quantum well HFETs, PnP AlSb/InAs/AlSb double heterojunction bipolar transistors (DHBTs), and InP/GaAsSb/InP NpN DHBTs. Whereas Sb- containing heterostructure devices have so far largely maintained the status of laboratory curiosity, recent developments in InP/GaAsSb DHBTs suggest they may break into commercial applications in the very near future.

10 citations


Journal ArticleDOI
TL;DR: In this article, a common contact to both n and p Ga-based antimonide materials has been developed for serial wiring of quaternary monolithic interconnected module thermophotovoltaic devices.
Abstract: A common contact to both n and p Ga-based antimonide materials has been developed for serial wiring of quaternary monolithic interconnected module thermophotovoltaic devices. The contact consists of a multilayer stack of Pd/Ge/Au/Ti/Au. Circular transmission line model measurements yield a specific contact resistance as low as 10 -5 Ω cm 2 for contacts to n-GaSb and 10 -4 Ω cm 2 for contacts to p-GaSb without annealing. Further reduction in specific contact resistance can be obtained for contacts annealed in nitrogen ambient for 10 s at 250-300°C. Cell isolation and thermophotovoltaic diodes fabricated using the five-layer metallization for both the p- and n-type contact exhibit current-voltage characteristics equivalent to diodes formed using multilayer metallization for the n-type contact and standard Ti/Au for the p-contact. While annealing improves contact properties, excessive annealing can lead to diffusion of the metallization into the semiconductor and lead to device degradation.

10 citations



Journal ArticleDOI
TL;DR: In this paper, the structure of a ternary compound, MoSb2S, was identified by single-crystal X-ray diffraction, which was synthesized by heating the elements in stoichiometric ratios in sealed silica tubes at 600−800 °C using small amounts of I2 as a mineralizator.
Abstract: The structure of a new ternary compound, MoSb2S, was identified by single-crystal X-ray diffraction. The title compound was synthesized by heating the elements in stoichiometric ratios in sealed silica tubes at 600−800 °C using small amounts of I2 as a mineralizator. The compound crystallizes in a new structure type in the monoclinic space group C2/m [a = 36.157(3) A, b = 6.3823(5) A, c = 6.5379(5) A, β = 95.093(2)°, Z = 16, R1/wR2 = 0.035/0.059]. Its crystal structure contains CdI2-related layers (MoSbS) and Sb columns, namely a zigzag (cis-trans) chain and an equidistant ladder, both of which are located between the MoSbS layers. The results of thermoelectric measurements and electronic structure calculations indicate metallic properties.

Journal ArticleDOI
TL;DR: In this article, the authors report on several studies of epitaxial growth parameters and their influence on defect formation in ideal antimonide superlattices (ASL) and show that defect density and size are critically dependent on growth temperature, with an optimal growth window between 480 and 500 °C.
Abstract: While physical properties of ideal antimonide superlattices (ASL) indicate that they should significantly outperform mercury cadmium telluride (MCT) based infrared photodiodes for low dark current applications in the long and very long wave-infrared (LWIR and VLWIR), this potential has not yet been fully realized. Even though measured Auger and tunneling rates in ASL's are reduced as predicted, overall carrier lifetimes remain much shorter, and dark currents much higher than expected. The large carrier losses are the result of defects in the ASL structure, with contributions measured from large bulk defects and surface channels along mesa sidewalls, and the remaining component believed to be due to midgap states. In this presentation we report on several studies of epitaxial growth parameters and their influence on defect formation. X-ray photoelectron spectroscopy analysis of oxide desorption from GaSb substrates shows the presence of both antimony and gallium oxides, along with their decomposition and desorption behavior with anneal temperature. A study of buffer growth shows that defect density and size are critically dependent on growth temperature, with an optimal growth window between 480 and 500 °C.. Side-by-side GaSb buffer growths on vicinal ((100) + 1 ° (111)) and flat (100) substrates show that while growing on vicinal material can suppress mound formation, it does not yield epilayers as flat as can be obtained on (100) substrates grown under optimal conditons. Finally, the ratio of As to In flux during superlattice growth can be used to tune the lattice parameter both above and below that of GaSb, with strain-related defects appearing when the mismatch reaches roughly 0.1%.


Journal ArticleDOI
TL;DR: In this paper, the intensity noise spectrum was measured for antimonide based 1.3 /spl mu/m vertical-cavity surface emitting lasers with a modulation bandwidth of 5.7 GHz with an intrinsic maximum frequency response that exceeds 28 GHz.
Abstract: The intensity noise spectrum is measured for antimonide based 1.3 /spl mu/m vertical-cavity surface emitting lasers. Analysis of the noise spectra indicates a modulation bandwidth of 5.7 GHz with an intrinsic maximum frequency response that exceeds 28 GHz. A discontinuity in the relaxation oscillation resonance frequency is observed, which suggests that the lasing behavior at threshold is assisted by nonlinearities in the gain medium.

Journal ArticleDOI
TL;DR: In this article, the metal-organic chemical vapor deposition (MOCVD) growth of InAsSb/InAs and GaSbN/GaAs MQW structures was described.
Abstract: We describe the metal-organic chemical vapor deposition (MOCVD) growth of InAsSb/InAs and GaAsSb/GaAs(P) multiple quantum well (MQW) and InAsSb/InAsP and InAsSb/InPSb strained-layer superlattice (SLS) active regions for use in mid-infrared emitters. We also describe the growth and initial characterization of GaAsSbN/GaAs MQW structures. By changing the layer thickness and composition of the InAsSb SLSs and MQWs, we have prepared structures with low temperature (<20 K) photoluminescence wavelengths ranging from 3.2 to 6.0μ m. We have made gain-guided, injection lasers using undoped, p-type AlAs0.16Sb0.84 for optical confinement and both strained InAsSb/InAs MQW and InAsSb/InAsP and InPSb SLS active regions. The lasers and LEDs utilize the semi-metal properties of a p-GaAsSb/n-InAs heterojunction as a source for electrons injected into the active regions. Cascaded, semi-metal, mid-infrared, injection lasers with pseudomorphic InAsSb multiple quantum well active region lasers and LEDs are reported. We also report on GaAsSb/GaAs(P) lasers and LEDs emitting at 1.1 to 1.2 μm grown on GaAs substrates and using AlGaAs layers for confinement.

Journal ArticleDOI
TL;DR: In this article, a large scale investigation into the effects of alloy layer disorder on emission in antimonide-based superlattices is reported, and the potential utility of these systems in infrared (IR) optoelectronic technologies is reviewed and issues inhibiting their realization identified.
Abstract: A large scale investigation into the effects of alloy layer disorder on emission in antimonide-based superlattices is reported. The potential utility of these systems in infrared (IR) optoelectronic technologies is reviewed and issues inhibiting their realization identified. The Ga0.7In0.3Sb alloy layer is modeled using both the conventional virtual crystal approximation and models which describe microscopic disorder, clustering, and atomistic relaxation. The structures have recently been fabricated for IR laser applications and we investigate the influence of the alloy description on the emission line shapes. For each superlattice we find that the emission linewidth and peak height is very sensitive to the microscopic details of the alloy potential. Comparing the various superlattice systems, which differ regarding the InAs layer widths, we find that their linewidth values (eV) are each of the same order of magnitude for a given population of excited carriers. While values show a strong dependence on the...

Journal ArticleDOI
TL;DR: In this paper, a photonic-crystal distributed-feedback (PCDFB) laser with an antimonide type-II "W" active region was studied theoretically and experimentally.
Abstract: The far-field emission and spectral characteristics of a photonic-crystal distributed-feedback (PCDFB) laser with an antimonide type-II ‘W’ active region were studied theoretically and experimentally. A 2nd-order grating was defined on a 2D rectangular lattice tilted by 20° relative to the facet normal, using optical lithography and dry etching. For pulsed optical pumping, the emission line centred on λ = 4.6–4.7 μm was up to an order of magnitude narrower (7–10 nm) than those of Fabry-Perot and angled-grating DFB (α-DFB) lasers fabricated from the same wafer. The PCDFB beam quality was also substantially enhanced, for example, by a factor of 5 compared to the α-DFB at a pump-stripe width of 200 μm. Theoretical simulations based on a self-consistent time-domain Fourier-transform simulation confirm significant advantages of the PCDFB laser over an α-DFB geometry.

Journal ArticleDOI
TL;DR: BaAuSb is a barium gold antimonide with ZrBeSi, which adopts the space group P63/mmc as discussed by the authors, with an Au-Sb distance of 2.7402
Abstract: The title compound, barium gold antimonide, BaAuSb, is isostructural with ZrBeSi, which adopts the space group P63/mmc. The Au and Sb atoms form planar honeycomb layers, with an Au—Sb distance of 2.7402 (3) A.

Patent
25 Jan 2002
TL;DR: In this paper, an n-type thermoelectric conversion material comprises a cobalt antimonide compound of filled skutterudite structure where a void small lattice with no antimony ring present is partially filled with a filling element.
Abstract: PROBLEM TO BE SOLVED: To provide an n-type thermoelectric conversion material excellent in thermoelectric conversion characteristics. SOLUTION: An n-type thermoelectric conversion material comprises a cobalt antimonide compound of filled skutterudite structure where a void small lattice with no antimony ring present is partially filled with a filling element, among crystal small lattices of the cobalt antimonide compound of skutterudite type crystal structure, with a cobalt of a component element replaced with palladium by 1-10 atom %.

Journal ArticleDOI
TL;DR: Vanadium nickel antimonide, VNi0.26 sb, adopts a partly filled NiAs-type structure as mentioned in this paper, with V atoms coordinated octahedrally and Ni atoms coordinated trigonal bipyramidally.
Abstract: Vanadium nickel antimonide, VNi0.26 (2)Sb, adopts a partly filled NiAs-type structure. It has an ordered atomic arrangement, with V atoms coordinated octahedrally [V—Sb 2.8073 (3) A] and Ni atoms coordinated trigonal bipyramidally [Ni—Sb 2.4553 (3)–2.7221 (3) A] by Sb atoms.

Book ChapterDOI
01 Jan 2002
TL;DR: In this paper, it was shown that surface reconstruction, in particular, the formation of surface dimer bonds, plays a key role in the ordering process, and that this model is currently the one most able to explain the majority of the observed ordering behaviour in group III-V and group IV alloy semiconductor layers grown on near (001) orientation substrates.
Abstract: Group III-V antimonide semiconductor alloys exhibit several types of atomic ordering when grown by molecular-beam epitaxy and metal-organic vapour-phase epitaxy. This chapter describes in detail the ordered structures that are observed and discusses in depth the current understanding of the origin of the ordering. The atomic ordering is, in general, induced at the surface during growth. The type of ordering observed is shown to depend on the growth technique and the structure of the growth surface. For (001) surfaces, it is found that surface reconstruction, in particular, the formation of surface dimer bonds, plays a key role in the ordering process. Growth of layers with different surface reconstructions results in distinct types of atomic ordering. A segregation of different-sized atoms that is driven by dimer-induced subsurface stresses is believed to occur. This lowers the strain energy associated with the surface dimerisation and accommodation of the different-sized atoms at the reconstructed growth surface. Surface atomic steps play an important role in “phase-locking” consecutively ordered surface layers. It is concluded that this model is currently the one most able to explain the majority of the observed ordering behaviour in group III-V and group IV alloy semiconductor layers grown on near (001) orientation substrates.

Journal ArticleDOI
TL;DR: In this paper, the material Sc2Sb was synthesized from the elements in a sealed tantalum ampoule at 1075 Κ for 4 days, and the powder was compressed to a pellet and melted twice in an arc furnace in a protective argon atmosphere.
Abstract: SbSc2, tetragonal, PAInmm (No. 129), a = 4.211(1) Â, c = 7.814(3) Â, V= 138.6 Â, Z= 2, R&(F) = 0.065, wÄreffF^ = 0.159, Τ =293 Κ. Source of material Sc2Sb was synthesized from the elements in a sealed tantalum ampoule at 1075 Κ for 4 days. The powdered product was compressed to a pellet and melted twice in an arc furnace in a protective argon atmosphere. After additional annealing at 1225 Κ for 8 days crystals of sufficient quality for X-ray diffraction were formed. Table 1. Data collection and handling.

Proceedings ArticleDOI
10 Dec 2002
TL;DR: In this paper, structural and optical properties of antimonide/arsenide interfaces are investigated on InAs/AlSb and inAs/GaSb superlattices with different types of interfaces.
Abstract: Quantum cascade lasers (QCLs) based on antimonide/arsenide heterostructures are promising candidates for room temperature high-efficiency semiconductor lasers operating in the mid-infrared (3-5/spl mu/m). The basic unit of such QCLs is made from InAs/GaSb/AlSb quantum wells (QWs) slightly strained on GaSb substrates. In this paper, we describe some key growth issues for mid-infrared electroluminescent devices based on a quantum-cascade design using InAs/GaSb/AlSb heterostructures grown on GaSb substrates. Structural and optical properties of antimonide/arsenide interfaces are first investigated on InAs/AlSb and InAs/GaSb superlattices (SL) with different types of interfaces. We use high resolution X-ray diffraction (HRXRD) to extract individual layer thicknesses.

01 Jan 2002
TL;DR: In this article, the electronic structure of the intermetallic compound uranium antimonide (USb) has been analyzed using solid state methods such as solid-state methods, and ab-initio calculations of the structure of USb have been performed.
Abstract: We present here ab-initio calculations of the electronic structure of the intermetallic compound uranium antimonide (USb), using solid state methods such as...

ReportDOI
10 Oct 2002
TL;DR: In this article, the authors used PC-1D simulations to evaluate the photoconductivity response of antimonide-based substrates and doubly-capped epitaxial layers and determine how to extract the recombination parameters using experimental results.
Abstract: RF photoreflection measurements and PC-1D simulations have been used to evaluate bulk and surface recombination parameters in antimonide-based materials. PC-1D is used to simulate the photoconductivity response of antimonide-based substrates and doubly-capped epitaxial layers and also to determine how to extract the recombination parameters using experimental results. Excellent agreement has been obtained with a first-order model and test structure simulation when Shockley-Reed-Hall (SRH) recombination is the bulk recombination process. When radiative, Auger and surface recombination are included, the simulation results show good agreement with the model. RF photoreflection measurements and simulations using PC-1D are compatible with a radiative recombination coefficient (B) of approximately 5 x 10{sup -11} cm{sup 3}/s, Auger coefficient (C) {approx} 1.0 x 10{sup -28} cm{sup 6}/s and surface recombination velocity (SRV) {approx} 600 cm/s for 0.50-0.55 eV doubly-capped InGaAsSb material with GaSb capping layers using the experimentally determined active layer doping of 2 x 10{sup 17} cm{sup -3}. Photon recycling, neglected in the analysis and simulations presented, will affect the extracted recombination parameters to some extent.

Journal ArticleDOI
TL;DR: In this paper, a small M atoms were incorporated into the cubic Sb/Te cage in an attempt to create the rattling effect as found in the filled skutterudites that attracted wide interest for their outstanding thermoelectric properties.
Abstract: Typically, useful thermoelectrics are small-gap semiconductors. Mo3Sb7 would be an interesting candidate, if it were not metallic. Electronic structure calculations reveal that metallic Mo3Sb7 can be made semiconducting by heavy doping, e.g., by replacing Sb in part with Te. We succeeded in the preparation of semiconducting Mo3Sb5-xTe2+x with enhanced thermoelectric properties. Furthermore, we incorporated small M atoms into the cubic Sb/Te cage in an attempt to create the rattling effect as found in the filled skutterudites that have attracted wide interest for their outstanding thermoelectric properties.

Patent
30 Aug 2002
TL;DR: In this paper, a thermoelectric material that has improved the conversion performance and junction properties with an electrode to a thermal history in an antimonide material having skutterudite structure was provided.
Abstract: PROBLEM TO BE SOLVED: To provide a thermoelectric material that has improved thermoelectric conversion performance and junction properties with an electrode to a thermal history in an antimonide thermoelectric material having skutterudite structure. SOLUTION: Gas atomized powder having a different antimony content is sintered by a thermoelectric material sintered body containing rare-earth elements in antimonide having skutterudite structure, thus forming a section containing antimony more excessively than a desired stoichiometric composition in one portion of the sintered body.

Proceedings ArticleDOI
06 Aug 2002
TL;DR: Modified liquid phase epitaxy (LPE) techniques can be adapted for the growth of relatively thick (50 to 500 micron) epitaxial layers of ternary and quaternary Ill-V antimonide alloys as discussed by the authors.
Abstract: Modified liquid-phase epitaxy (LPE) techniques can be adapted for the growth of relatively thick (50 to 500 micron) epitaxial layers of ternary and quaternary Ill-V antimonide alloys, including InAsSb, InGaSb, AlGaAsSb, InGaAsSb, and InAsSbP. These structures can function as 'virtual' substrates with adjustable lattice constants for epitaxy of various optoelectronic devices such as mid-infrared photodiodes. A variety of substrate structures can be realized either by effecting gradual, continuous compositional grading of thick epilayers, or by growing multilayers with abrupt but incremental compositional changes between adjacent layers. Both approaches can be combined with selective removal of the seeding substrate and wafer bonding techniques. Low-defect alloy substrates with increased functionality, and with lattice constants and bandgaps significantly different than available with binary compound wafers (e.g., InAs or GaSb), appear feasible.

Journal ArticleDOI
TL;DR: Ce2Sb as mentioned in this paper is a tetragonal, 14/mm, 3D structure of tetraeuropium diantimonide oxide, which is formed by condensed SbCeç mono-capped square antiprism.
Abstract: Ce2Sb, tetragonal, 14/mmm (No. 139), a = 4.538(1) Â, c = 17.861(3) Â, V= 367.8 Â, Z = 4, R#(F) = 0.031, wRKf(F) = 0.076, T= 293 K. Source of material Ce2Sb was synthesized from the elements in a sealed tantalum ampoule at 1675 Κ for 4 hours. Single crystals were obtained from slowly cooled samples (cooling rate: 25 K/h). Discussion Ce2Sb belong to the i/12 structure type of La2Sb as shown by Borsese et al. [1] from powder diffraction data. The strong bonded heteroatomic 3D framework ^[Sb(Ce 1)4/4^2)5/5] is formed by condensed SbCeç mono-capped square antiprism Table 2. Atomic coordinates and displacement parameters (in Â). (d(Sb—Cel) = 3.344( 1 ) À (4x); d(Sb—Ce2) = 3.276( 1 ) À ( 1 x), 3.293(1) À (4x). The nearest neighbours of the Ce2 atoms are five Sb atoms arranged at the corners of a square pyramid, forming NaCl type fragments. The short Ce l—Cel distances of about 3.209 Â in the non-capped square of the SbCeg polyhedra indicate additional Ce—Ce interaction in the 4 4 nets of Cel (see figure). Obviously this leads to the large c!a ratio (3.936 » 3.414 = V2+2) compared with that of e.g. Eu4Sb20 [2] (K2N1F4 structure type). Consequently, the final difference Fourier synthesis gave no evidence for an interstitial atom in the quasi-octahedral Cee cavities (see also [3]). Table 1. Data collection and handling. Crystal: dark, metallic lustre. size 0.1 xO.l χ 0.2 mm Wavelength: Mo Ka radiation (0.71073 λ ) μ· 313.41 cm\" Diffractometer, scan mode: STADI4, Stoe, 20/cu 20m»: 74.92° N 2 a(Iobs), 302 N(param)„fxno¡: 11 Programs: SHELXL-97 [4], ATOMS [5] References 1. Borsese, Α.; Bolzone, G.; Mazzone, D.; Ferro R.: Heats of formation of Ce-Sb Alloys. J. Less Comm. Met. 79 (1981) 57-63. 2. Schaal, H.; Nuss, J.; Hönle, W.; Grin, Yu.; von Schnering, H. G.: Crystal structure of tetraeuropium diantimonide oxide, Eu4Sb20. Z. Kristallogr. NCS 213 (1998) 15. 3. Wang, Y.; Calvert, L. D.; Taylor, J. B.: Is there an oxygen atom in LaîSb? Acta Crystallogr. B36 (1980) 220-221. 4. Sheldrick, G. M.: SHELXL-97. Program for crystal structure refinement. University of Göttingen, Germany 1997. 5. Dowty, E.: ATOMS (V 5.1). Shape Software, Kingsport, USA 1999. Atom Site X y ζ Un U22 t/33 t/12 1/13 t/23 Ce(l) 4c 0 1/2 0 0.0127(3) 0.0214(4) 0.0115(3) 0 0 0 Ce(2) 4e 0 0 0.17903(4) 0.0103(2) t/11 0.0104(3) 0 0 0 Sb 4e 0 0 0.36247(4) 0.0101(2) Un 0.0107(3) 0 0 0 * Correspondence author (e-mail: j.nuss@fkf.mpg.de)

Proceedings ArticleDOI
10 Dec 2002
TL;DR: In this article, the molecular beam epitaxy of advanced heterostructures containing mixed arsenide/antimonide layers presents a number of special challenges, such as the need for precise control of alloy composition over time and reproducible manipulation of the interfacial chemistry across very thin III-As and III-Sb layers on the other.
Abstract: The molecular beam epitaxy of advanced heterostructures containing mixed arsenide/ antimonide layers presents a number of special challenges. A 5 /spl mu/m thick laser designed to emit mid-infrared radiation of 4 /spl mu/m wavelength, for example, may incorporate thick (/spl sim/2 /spl mu/m) lattice-matched AlGaAsSb layers for optical confinement, thinner (/spl sim/0.1 /spl mu/m) lattice-matched InGaAsSb layers for electrical confinement, and extremely thin (/spl sim/20 /spl Aring/) InAs and InGaSb layers as quantum wells. Such structures highlight the need for precise control of alloy composition over time on the one hand, and reproducible manipulation of the interfacial chemistry across very thin III-As and III-Sb layers on the other.