Study on Stereochemical Activity of Lone Pair Electrons in Sulfur and Halogen Coordinated Antimony(III) Complexes by 121Sb Mössbauer Spectroscopy

We have measured ¹²¹Sb Mössbauer spectra at 20 K for 52 compounds of antimony(III). An Sb(III) atom with the electron configuration [Kr] 4d ¹⁰5s ² has a lone pair electrons. The stereochemical property of the lone pair has been found to depend very much on the kinds of atoms surrounding the antimony atom and the configurations of the coordinating atoms.     

Behavior of antimony above solid solubility in silicon produced by implantation and laser annealing

Abstract

Antimony implantation into <111> silicon was carried out at RT with a dose of 4.5 × 10¹⁵ cm^?2, energy 75 keV. For the annealing of the sample pulses of a Q-switched ruby laser were used with energy density of ～ 1.5 Joule/cm² and duration of 15–20 nsec. Hall effect measurement was applied to determine the electrical activity of the layers. Lattice location and the depth profile of Sb was studied by RBS and channeling technique. Measurements show that after laser annealing Sb occupies mostly substitutional sites in Si with 84% electrical activity. It has been shown that after laser annealing the concentration of Sb in lattice sites is almost an order of magnitude higher than the limit of solid solubility. Isochron and isothermal annealing of these samples up to 1150°C was carried out to study the kinetics of reverse annealing of antimony.     

Evaluation of structural and electrochemical properties of the MnSb–Li system as anode for Li-ion batteries

The electrochemical reaction mechanisms between lithium and cystalline MnSb are investigated by X-ray diffraction, ¹²¹Sb Mössbauer spectroscopy, and X-ray absorption spectroscopy (XAS). The analysis of the experimental data at different depths of the electrochemical discharge process reveals a complex reaction mechanism comprising two steps. The main reaction of the first step corresponds to the dispersion of lithium in the MnSb matrix with formation of the intermediate compound LiMnSb. The second step corresponds to a Li–Sb alloying process with formation of Li₃Sb.     

Normal coordinate analysis and quantum chemical study of tris(p-fluorophenyl)antimony di(N-phenylglycinate) [(p-FC6H4)3Sb(O2CCH2NHC6H5)2]

A complete normal coordinate analysis was performed by two different methods: a classical Wilson’s G-F matrix method and the semi-empirical molecular orbital PM3 method, for a five coordinate tris(p-fluorophenyl)antimony di(N-phenylglycinate) [(p-FC₆H₄)₃Sb(O₂CCH₂NHC₆H₅)₂], known to be an in vitro antitumour molecule.      

Effect of antimony doping on the low‐temperature performance of solution‐processed indium oxide thin film transistors

The effects of antimony (Sb) doping on solution‐processed indium oxide (InO_x) thin film transistors (TFTs) were examined. The Sb‐doped InSbO TFT exhibited a high mobility, low gate swing, threshold voltage, and high I_ON/OFF ratio of 4.6 cm²/V s, 0.29 V/decade, 1.9 V, and 3 × 10⁷, respectively. The gate bias and photobias stability of the InSbO TFTs were also improved by Sb doping compared to those of InO_x TFTs. This improvement was attributed to the reduction of oxygen‐related defects and/or the existence of the lone‐pair s‐electron of Sb³⁺ in amorphous InSbO films. (© 2014 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

Temperature dependence study of the quadrupole interaction of111Cd in antimony

A power law dependence has been observed for the temperature dependence of the quadrupole interaction of the 247 keV state of¹¹¹Cd in antimony, which is similar to that observed for¹²¹Sb and¹²³Sb in antimony.Supported in part by the US Energy Research and Development Administration.     

Calibration of the isomer shift of121Sb and119Sn by means of Mössbauer spectroscopy and molecular orbital calculation

The relationship between the isomer shifts in Mössbauer spectroscopy and the electron contact densities has been investigated for several antimony and tin compounds. Mössbauer spectra for¹²¹Sb in rapidly frozen solutions of antimony compounds were measured. The isomer shifts are compared with the valence electron densities at the antimony nucleus calculated with theab initio molecular orbital method. The relative difference of the nuclear charge radius ΔR/R could be obtained as ΔR/R =?(10.2±1.0)×10^?4 for the 37.15 keV M1 transition of¹²¹Sb. Further, some computations of the electron density at the tin nucleus for several tin compounds were performed. By comparing the valence electron contact densities with isomer shifts, which had been reported for several tin compounds in rare-gas matrix states, the value of ΔR/R for 23.87 keV M1 transition in¹¹⁹Sn was estimated to be (1.57±0.03)×10^?4.     

121Sb and127I Mössbauer spectroscopic study on Sb-I hypervalent bonds in trigonal bipyramidal antimony(V) complexes

Both¹²¹Sb and¹²⁷I Mössbauer parameters at 20 K were obtained for six organoantimony(V) complexes, having trigonal bipyramidal geometry around the antimony atoms. Characteristics of the apical Sb-I hypervalent bonds were deduced from the above parameters and also from the¹²¹Sb Mössbauer parameters of eight trigonal bipyramidal antimony complexes with other halogen atoms than iodine.     

Estimation of the value of ΔR/R for121Sb nucleus by means of Mössbauer spectroscopy and molecular orbital calculation

The¹²¹Sb Mössbauer spectra of rapidly frozen solutions of antimony compounds were observed. The isomer shifts were compared with the electron density at the antimony nucleus calculated with the ab initio molecular orbital method. A value ΔR/R=?(11±2)×10^?4 was derived for the 37.15 keV M1 transition of¹²¹Sb.     

Graphene Nanosheets Suppress the Growth of Sb Nanoparticles in an Sb/C Nanocomposite to Achieve Fast Na Storage

Presently, graphene incorporation is one of the most effective strategies to develop superior electrode materials for sodium‐ion batteries (SIBs). Herein, it is excitingly found that an incorporated graphene nanosheet in the preparation processes can not only completely protect all the Sb nanoparticles in an Sb/C composite from being inactivated, but also suppresses their growth to undesirable micrometer size. While there are still many exposed Sb particulates on the surface of pristine Sb/C microplates, the graphene‐incorporated Sb/C/G nanocomposite consists of uniform Sb nanoparticles of 20–50 nm, all of which have been protected by and wrapped in the mixed carbon network. When used as anode materials for SIBs, the Sb/C/G nanocomposite exhibits the best Na‐storage properties in terms of the highest reversible capacity (650 mA h g^?1 at 0.025 A g^?1), fastest Na‐storage ability (290 mA h g^?1 at a high current density of 8 A g^?1), and optimal cycling performance (no capacity decay after 200 cycles), in comparison to pristine Sb/C and pure Sb. It is further revealed that the much enhanced performance should originate from the improvement of Na‐storage kinetics and increase of electronic conductivity via comparing the electrochemical impedance spectra, and cyclic voltammetry profiles, as well as the polarization variation along with current densities.     

Temperature dependence of the electric field gradient for111Cd in antimony

For the temperature dependence of the electric field gradient of¹¹¹Cd in the semimetal antimony the well knownT ^3/2 relationship is valid over a wide temperature range. The slope parameterB differs from that for^{121, 123}Sb in antimony by a factor of about 2.3.     

Multi-band spectra of odd and even nuclei of the s-d shell

The energy levels of^{21, 23}Na,^{22, 23}Ne,^{24, 28}Mg and^{25, 29}Al are obtained by mixing various bands using the projected deformed Hartree-Fock (DHF) method. Solutions having minimum energies are found to be prolate for all the nuclei considered here. Higher bands are obtained either by considering particle-hole excitations or oblate solutions. These various bands are mixed using the projection method and care has been taken to orthogonalize the bands. The interactions used in this study are those given by Kuo, Preedom-Wildenthal (PW) and WHMK interactions. The last one seems to give good results for most of the nuclei considered here. Not only are the lowest bands well-reproduced but the second lowest bands agree reasonably well in most nuclei. The third lowest ones obtained in some nuclei are not yet observed as complete bands. However, K obtained for the third band seems to be correct. A comparison with shell model calculations—which are numerically exhausting—shows similar results for the lowest band. However, the agreement of the second band varies from nucleus to nucleus. A comparison between matrix elements of the interactions is made to analyze the results.     

A RHEED study of the growth of antimony on clean tungsten (100)

The epitaxy of antimony, vapour deposited onto atomically clean W(100) in UHV, has been studied from submonolayer up to 60 equivalent monolayers in thickness. The resulting initial surface structures and subsequent three dimensional antimony islands were determined by in situ reflection high energy electron diffraction. For deposition rates of less than three monolayers/minute a series of submonolayer structures were followed by a (1 × 1) pseudomorphic antimony layer. Continuing deposition led to the formation of two types of three dimensional islands growing out of the pseudomorphic layer, one identical with bulk antimony, the other an abnormal fcc phase but with the same lattice constant. Both were oriented such that Sb(100)z.dfnc; W(100) and Sb 〈110〉 z.dfnc; W 〈110〉. Previously a growth sequence differing from that described above has been reported which involves an initial amorphous overlayer and subsequent spontaneous crystallisation. This type of growth could also be duplicated in our experiments for deposition under poor conditions of cleanliness (pressure exceeding 10^?8 Torr) and faster deposition rates (> 10 monolayers/minute).     

Low-energy antimony implantation in silicon

Abstract

Antimony is known to be a donor in silicon, Low-energy implantations of Sb in Si produce very shallow profiles which have many device applications. Gibbons et al. ¹ calulated the projected ranges of Sb ion-implanted in Si, using the LSS (Lindhard, Scharff, and Schiott) method. Oetzmann et al. ² measured projected ranges and range straggling for several heavy ions in Si, Al, and Ge, using high-resolution backscattering; in the energy region of interest to us, e = 10^?2 to 10^?1, their results were about 30% higher than those reported by Gibbons et al. In the study reported here, we implanted 5 × 10¹⁴ Sb/cm² in Si at 5–60 keV, measured the resulting depth distribution by secondary ion mass spectrometry, and checked the measurements by backscattering. Our results showed the experimental projected ranges to be about halfway between those reported in the earlier studies. The discrepancies between theoretical calculations and experimental results are due not to the electronic stopping cross section, which is negligible in the range of interest here, but to the nuclear stopping power. Using a modified nuclear scattering potential given by Wilson et al.,³ we calculated the projected range distribution according to the method described by Winterbon.⁴ Our results are in very good agreement with the experimental measurements.     

121Sb Mössbauer studies on some antimony III chalcogenides and chalcogenohalides. Application to the structural approach of sulfide glasses

This study concerns antimony chalcogenides and iodochalcogenides isolated in the systems: M¹ ₂S-Sb₂S₃ (M^I=Li, Tl), Sb₂X₃-SbI₃, SnX-SbI₃ (X=S, Se, Te) and Sb Se –Sb Te. The crystal structure determination of these compounds was carried out. As all elements with pair antimony III atoms show varied environments by sulphur and iodine atoms in terms of activity of its 5s² non-bonding electron. Mössbauer effect of¹²¹Sb leads to the determination of the local electron environment and to complete the crystal structure analysis. Evolution of Mössbauer data is related to antimony III environment type, bond lengths and activity of non-bonding electron pair. These results have been used to give a structural approach of glass forming region in the Tl₂S-Sb₂S₃ system.     

氢化物发生-原子荧光法直接测定锑及其化合物中的硒和铋

通过研究在不同酸度下Sb5+对Se,Bi的干扰情况,发现在高酸度下,Sb对Se,Bi的干扰明显减弱,并结合锑在不同价态发生氢化反应的差异性,建立了不需通过任何化学分离而直接测定锑及其相关产品中的微量硒和铋的方法,并用于实际样品的分析.方法对实际样品加标回收率在95%～105%之间,检测下限(含量)硒和铋分别为0.00004×10-2mg@L-1和0.0001×10-1mg@L-1,对实际样品分析精度分别为RSD(Se)=2.4%(含量为0.00169×10-2mg@L-1时),5.4%(含量为0.00056×10-mg@L-1时)和RSD(Bi)=5.0%(含量为0.00024×10-2mg@L-1时),1.3%(含量为0.00229×10-2mg@L-1时),完全满足实际样品分析的要求.     

Mössbauer spectroscopic study of half-Heusler compounds

The family of half-Heusler compounds offers a variety of half-metallic ferromagnetic materials. We have applied the Mössbauer spectroscopy to study the atomic order, local surroundings and hyperfine fields to several half-Heusler compounds. ¹²¹Sb Mössbauer study of the compound CoMnSb revealed the presence of two nonequivalent antimony positions in the elementary cell and enabled to identify the structure. ^119mSn, ¹⁵⁵Gd and ¹⁹⁷Au Mössbauer spectroscopic studies were used to characterize the properties of ferromagnetic granular material based on the half-Heusler ferromagnet MnAuSn in the antiferromagnetic GdAuSn matrix.     

Interaction between antimony atoms and micropores in silicon

The interaction between Sb atoms and micropores of a getter layer in silicon is studied. The getter layer was obtained via implantation of Sb⁺ ions into silicon and subsequent heat treatment processes. The antimony atoms located in the vicinity of micropores are captured by micropores during gettering annealing and lose its electrical activity. The activation energy of capture process to the pores for antimony is lower than that of antimony diffusion in silicon deformation fields around microvoids on the diffusion process.     

Electrodeposition of Sb2Se3 on indium-doped tin oxides substrate: Nucleation and growth

The mechanisms related to the initial stages of the nucleation and growth of antimony selenide (Sb₂Se₃) semiconductor compounds onto the indium-doped tin oxides (ITO) coated glass surface have been investigated using chronoamperometry (CA) technique. The fabrication was conducted from nitric acid bath containing both Sb³⁺ and SeO₂ species at ambient conditions. No underpotential deposition (UPD) of antimony and selenium onto ITO substrate was observed in the investigated systems indicating a weak precursor-substrate interaction. Deposition of antimony and selenium onto ITO substrate occurred with large overvoltage through 3D nucleation and growth mechanism followed by diffusion limited growth. FE-SEM and XRD results show that orthorhombic phase Sb₂Se₃ particles with their size between 90 and 125 nm were obtained and the atomic ratio for antimony and selenium was 2:2.63 according to the EDX results.     

The study of the nuclear reactions for the production of antimony isotopes

Nuclear reactions using proton beams and tin targets are studied in order to obtain antimony radionuclides. A new target system that includes on-line monitoring of target heating is used. To determine the parameters of proton beams, experimental studies on nuclear reactions are performed using Ti, Cu and stainless steel targets. Using modern model approximations, cross sections are determined for the formation of radionuclides ¹¹⁹Sb and ¹¹⁷Sb in the investigated nuclear reactions.