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Scanning thermal microscopy is applied to investigate the local thermal properties of thin phase-change (Ge2Sb2Te2) layers. It is demonstrated that the heated tip can be used to locally crystallize parts of an amorphous Ge2Sb2Te2 layer, thereby suggesting thermal probes may be used for data storage applications on phase-change media.

Research describing self-diffusion experiments with gallium and antimony are presented. In particular the differences in diffusion speed in isotope heterostructures are measured and possible mechanisms for diffusion are examined.

A detailed computational study of the occurrence of Sb segregation, using Sb(III) and Sb(V) ions on the (110) and (001) surfaces of SnO2, is reported and discussed.

Antimony (Sb) doping and its effects on the luminescence of lead tungstate single crystals were investigated.

Research was conducted to examine the electroluminescence (EL) performance of organic light emitting diodes (OLEDs) with a thick doped hole transport layer (DHTL). The basic cell structure is an anode/DHTL/HTL/emitter layer/cathode. Results indicate that the combination of a hole transport polycarbonate polymer and a tris (4-bromophenyl) amiium hexachroloantimonate as a dopant can form thick DHTL with yield an excellent EL performance. The EL characteristics of doped OLEDs are presented.

Research was conducted to examine systematically the As/Sb exchange on Sb-terminated and Ga(In)-terminated GaSb(001) surface by in situ real-time line-of-sight mass spectrometry (LOS-MS). It was shown that there was a critical As2 flux below which the LOS-MS Sb signal from a GaSb(001) surface with 1 monolayer of Ga or In disappears upon As2 exposure. This indicates that As/Sb exchange could be suppressed and interface broadening could be regulated to one atomic layer precision.

The heteropolyanions (Bi2W22O74(OH)2)12- and (X2W20M2O70(H2O)6)(14-2n)- (X = Sb3+, Bi3+; M(super n+) = Fe3+, Co2+, Zn2+) were synthesized as alkali metal and ammonium salts, respectively. They were characterized by elemental analysis, infrared spectroscopy and X-ray crystallography. These tungsto bismutates and antimonates have one common characteristic: the trivacant beta-B-XW9O33 Keggin fragment as the structural building unit.

A study was conducted to show that antimony segregation to the surface as Sb(III) in Sn(sub 1-x)Sb(sub x)O2 changes the effect of water vapor on the surface-catalyzed combustion rate of carbon monoxide and the elevated-temperature electrical conductivity. Coprecipitation was carried out to prepare the oxides. A computer-controlled rig was then utilized to determine the electric behavior of pellets under controlled humidity and temperature conditions.

The synthesis of a sulfur-bridged sandwich cubane-type molybdenum-antimony cluster compound ((H2O)9Mo3S4SbS4Mo3(H2O)9)(pts)8*24H2O from the incomplete cubane-type molybdenum cluster (Mo3S4(H2O)9)(super 4+) and antimony metal is described. The existence of the core was confirmed by X-ray crystallography, while 121Sb Mossbauer spectroscopy indicated that the oxidation state of antimony in 2*pts is III and the mean oxidation number of molybdenum is +3.5.

The structural properties of a series of compounds based on Sb(sub 3) as a nuclear unit were investigated using ab initio analysis. Specifically, the suitability of the Zintl-Klemm-Busmann principle on alkali-antimony clusters of the form A(sub 3)Sb(sub 3) and A(sub 4)Sb(sub 3)(super +) (A = Na, K, Rb) was analyzed. It was found that the structure of the 18 valence electron units pertaining to bonding, geometry and stability is analogous to the respective properties of the isoelectronic ozone molecule.

A study was conducted to examine the in and out-diffusion of phosphorus and antimony in gallium arsenide. The samples were annealed using concentration-depth profiles measured by catholuminescence spectroscopy. Results of the arsenic self-diffusion experiments revealed a negative value for the pressure exponent. The arsenic pressure exponent for the case of out-diffusion correlated with a substitutional-interstitial mechanism.

Research was conducted to study the residual defects in medium energy and low dose Sb ion-implanted silicon after annealing at 1000 degrees C for 10 and 30 minutes using advanced transmission electron microscopy methods and secondary ion mass spectrometry. A 5 nm probe was also utilized to carry out nano-area diffraction analysis while the silicon wafers were characterized by an electrical resistivity of 10 ohms cm. Results showed that annealing led to the disappearance of irregular shape defects and precipitates.

A comparison of the interfacial reactions of cobalt with differently doped Si0.8Ge0.2 layers epitaxially grown on silicon was performed during furnace annealing of up to 600 degrees C. Auger electron spectroscopy, x-ray diffraction, secondary ion mass spectroscopy and transmission electron microscopy were used as measurement tools while undoped and highly boron- or antimony-doped Si0.8Ge0.2 strained layers were utilized. Results revealed that both dopants accumulated at the surface but boron stayed trapped at the interface between a Co rich surface layer and the monosilicide.

Research was conducted to examine the preparation of allylic dihalophosphines, -arsines, and -stibines by reaction of allylic stannanes on phosphorus, arsenic, or antimony halides. The chemical properties of the allylic compounds as allylation reagents of aldehydes, the thermal rearrangement of the primary gamma-products and their reduction to form the corresponding primary allylic phosphines, stibines and arsines are also discussed. The properties of various allylic arsines and allylic phosphines were also analyzed.

Antimony (Sb) acts as a convenient, reliable and robust barrier to surface contamination. This was gleaned from an examination of the desorption behavior of Sb multilayers applied as a passivant to (001) GaAs, using reflection high-energy electron diffraction, reflectivity, Auger electron spectroscopy, x-ray photoelectron spectroscopy and thermal desorption. The characteristics obtained from the study will be useful in monitoring the progress of passivant desorption and substrate preparation for subsequent process steps.

The majority of the known binary phosphorus sulfides are quickly oxidized by triphenylantimony and triphenylarsenic sulfides, with the main mode of reactivity comprising the cage phosphorus oxidation through the attachment of an exocyclic sulfur. Sulfur is transferred to the most formally oxidated tricoordinate sulfur rather than to the tetracoordinate phosphorus sites or less formally oxidated phosphorus sites.

The antimony-alkyl sigma-bonded tetraphenylporphyrins of the general formula ((TPP)Sb(R)(L))+Y-, where R = CH3 or OCH3-, L = CH3, OH-, OCH3-, or F-, and Y = PF6 or ClO4 are synthesized and subjected to ESR spectroscopy, UV-visible spectroelectrochemistry and electrochemistry. All porphyrins exhibit stability upon exposure to air and moisture whereas melting points are established at greater than 250 degrees C. Their electrochemistry and spectroelectrochemistry in benzonitrile or dichloromethane, with 0.1 M tetrabutylammonium perchlorate, reveal two reversible reductions each.

Pentabismuth(3+) tetrachlorogallate(III) has been synthesized by the reduction of a BiCl3-GaCl3 melt with bismuth metal. The antimony analog Sb5(GaCl4)3 was prepared by the reduction of an SbCl3-GaCl3 mixture with gallium metal. Theoretical calculations showed for isoelectronic, trigonal pyramidal M5 closo-clusters showed the stability of the Sb(sub 5)(super 3+). The results showed the equal distribution of electron density over all M-M vectors for Sb(sub 5)(super 3+) and Bi(sub 5)(super 3+), while Sn(sub 5)(super 2-) and Pb(sub 5)(super 2-) have no substantial electron density between the equatorial atoms.

The antimony(III) bis-dmit (H2-dmit = 4,5-dimercapto-1,3-dithiole-2-thione) complexes (Y)Sb(dmit)2, where Y = Et4N (1) or Y = C7H10N (1,4-dimethylpyridinium) (2) are synthesized, and exhibit considerable metal-sulfur interanionic interaction in the solid state. In the complexes the anion Sb(dmit)2- constituting strong Sb-S bonds are ordered leading to pseudo trigonal bipyramidal antimony atoms. A polymeric two dimensional network is present in 1 but anionic dimers constitute the crystals of 2.

The edge inversion mechanism was proposed to explain the tetrahedron edge's movement to form a square planar transition state. This mechanism theory was supported by the measurement of the inversion activation free energy at the bismuth atom of three trivalent organobismuth compounds bearing a hexafluorocumyl alcohol ligand at variable temperatures using F NMR. The results supported the intramolecular coordination of the methoxy and the dimethylamino groups as stabilizers for the transition state of inversion at the bismuth atoms, the effect of the edge inversion mechanism.

Spectroscopic studies enable the characterization of primary unsaturated stibines ethenylstibine and ethynylstibine, resulting from a reaction between antimony trichloride and the respective vinyl- and alkynyltributylstannates. The synthesis proceeds through the formation of dichlorostibines, which on chemoselective reduction result in the desired products. Addition of solvents results in an oligomer due to the unstability of these stibines, which do not contain C-Sb multiple bonds.

The arylation of enones and enals by arylboron compounds in the presence of SbCl3 with a Pd catalyst yields the corresponding Michael-type conjugate addition compounds. The absence of SbCl3 leads to Heck-Type substitution products. Arylation proceeds through the formation of an arylpalladium species obtained by oxidative addition between Pd(0) and a C-B bond. This arylpalladium intermediate contains a carbonyl oxygen, which coordinates with SbCl3 to form an antimony enolate and finally the end products.

The syntheses of both the SbCl4+ cation and novel SbBr4+ cation as their Sb(OTeF5)6- salts are described. The compounds were prepared by oxidation of SB(OTeR5)3 with Cl2 and Br2, respectively. The salts were characterized by low-temperature Raman spectroscopy and X-ray crystallography and in solution at ambient temperature by 19F, 121Sb and 123Sb spectroscopy.

X-ray crystallography helps determine the crystal structures of Sb(CH3)5, Sb(C6H5)3(CH3)2 and Sb(CH3)(sub 6)(super -). Regular trigonal bipyramidal geometry is observed for all pentacoordinated species. A comparative study of the structures of Sb(V) and Bi(V) methyl compounds reveals the significant bond length differences between Sb and Bi compounds. Differences between axial and equatorial bond lengths in Sb compounds are higher than those in Bi compounds. Sb(CH3)(sub 6)(super -) exhibits octahedral geometry.

GaSb Sb structures grown heteroepitaxially by the molecular-beam epitaxy method are examples of the heteroepitaxy between the III-V compounds and group-V elements. Single-crystal Sb undergoes rapid nucleation on (III)A GaSb while GaSb grows well on (III) Sb and displays (III)A orientation. An epitaxial model helps simulate the growth characteristics of the Sb GaSb structures.

Radioactive tracers and anodic oxidation sectioning method are employed to measure self-diffusion coefficients of In and Sb in InSb single crystals. Self-diffusion coefficients are calculated and concentration profiles are analyzed after subtracting the dislocation contribution. Mass transport is analyzed by a mechanism involving migration via antisite formation.

Two polysulfide ligands in solid-state antimony compounds are synthesized from Cs2Sx fluxes at low temperatures. A combination of intermediate temperatures and alkali metal polychalcogenide fluxes is necessary for useful reaction media for synthesis of such compounds.

A reducing metal-centered sp excited state is responsible for the reactivity of antimony(III) hyper porphyrins whose photochemical and photophysical properties resemble simple coordination compounds belonging to main-group metals. Antimony porphyrins can be used as photocatalysts in various solar energy applications.

Electron-beam evaporation system is used to deposit amorphous Si:Sb alloy thin films with different concentrations of antimony (Sb) on Si substrates. Spectroscopic ellipsometry and x-ray diffraction techniques are used to determine the optical properties of the crystallized amorphous alloys. A reduction in the optical energy bond gap from 1.6 to 0.35 electron volts is observed.

The oxidative addition of H2S with XeF+SbF6- in HF yielded monofluorosulfonium hexafluoroantimonate. The synthesis was dependent on the nature of the solvent as evidenced from the behavior of H2SF+SbF6- in solution and in the solid state. The formation of hydrogen chloride in all the reactions of H2SF+SbF6- was considered to be the driving force of the reaction pathways. The salts formed were characterized by vibrational and NMR spectroscopy.

Diffusion and precipitation of antimony in highly doped delta layers in silicon were investigated using Rutherford backscattering spectrometry. The results showed that nuclei generation occurred either by the rapid and simultaneous generation of a limited number of nuclei with a subsequent diffusion-controlled growth or by slow continuous generation of a larger numberof nuclei at random sites in the delta plane with subsequent incorporation-controlled growth.

The influence of Sb on phase transformations of amorphous TiSi2 thin films was investigated using transmission electron microscopy and x-ray diffraction. The results showed that Sb incorporation caused the film to exhibit a higher crystallization temperature but a lower crystal growth rate. Activation energy decreased when the Sb content was increased. In general, Sb incorporation in the film enhanced the transformation process but inhibited crystallization.

The catalysis caused by the introduction of antimony(III) to the reduction reaction of 12-phosphomolybdate can be monitored to allow the kinetic-photometric identification of antimony(III). The reaction requires a micellar medium such as the nonionic surfactant Triton X-100 to facilitate the detection of the interactions between antimony(III) and the phosphate-heptamolybdate complex. The technique provides an efficient and highly selective procedure of determining the kinetics of antimony(III).

The reactions of S8, I2 and MF5 (M=As, Sb) in liquid SO2 yielded the crystallines S2I4(MF6)2. An analysis of the magnetic susceptibility of the salts showed a probable intrinsic paramagnetism. The X-ray crystal structures were determined by usage of an improved absorption correction. The isomerization enthalpies estimated showed greater thermodynamic stability of the observed pi S2I4(super 2+) in relation to the sigma-bonded isomer. It was concluded that pi bonds in S2I4(super 2+) were stable upon addition of I2.

The growth and magnetism of ultrathin Ni films on the (111) surface of Cu using Sb as a surfactant, in order to stimulate a layer-by-layer (LBL) growth mode, are analyzed. The results indicate that the inverse spin reorientation transition (SRT) of Ni on Cu(111) occurs at a thickness of 7-8 ML and it is also seen that Sb improves the LBL growth in this system.

Research describing the dopant behavior of antimony implanted into silicon is presented. In particular the effects of high energy ion irradiation on distribution and substitution are investigated.

The fabrication and magnetotransport properties of nanoscaled clusters of manganese antimonide (MnSb) grown on sulfur-passivated GaA(001) substrates by molecular-beam-epitaxy (MBE) are reported. Magnetotransport measurement is thought to be a powerful method to elucidate magnetic behaviors of nanoscaled magnetic dots.

One hundred years ago, John Brian Christopherson (1868-1955) discovered that antimony potassium tartrate was an effective treatment against schistosomiasis. Antimony had been previously used against visceral leishmaniasis, Trypanosoma brucei gambiense, [...]

The electronic spectra, redox chemistry and photophysical properties of monomeric antimony(III) and dihydroxoantimony(V) phthalocyanine derivatives in solution are discussed. The complexes, whose reduced and oxidized forms are soluble in polar solutions, have been proposed to be cations of the form ((Pc)Sb(III))+ and ((Pc)Sb(V)(OH)2)+. In ethanol solution, ((Pc)Sb(OH)2)F exhibits blue luminescence when excited by ultraviolet radiation.

Magnetic properties, microstructure and intercrystalline segregation of antimony were examined on 2.4 wt.% Si steels containing 0.005 to 0.047 wt.% Sb. The measured reduction of the total core losses in steels containing 0.040 and 0.047 wt.% Sb has various values for chosen variants of pre-annealing at 500 [degrees] C and 800 [degrees] C. The reduction of losses relates to selective segregation of antimony on grain boundaries during recrystallization.