Read by QxMD icon Read


Mattia Sist, Carlo Gatti, Peter Nørby, Simone Cenedese, Hidetaka Kasai, Kenichi Kato, Bo B Iversen
The discovery of the ultra-high thermoelectric figure of merit of 2.6 in SnSe has drawn attention to other lead-free IV-VI orthorhombic semiconductors. GeSe has been predicted to possess thermoelectric performances comparable to SnSe. Here, a complete structural study is reported of GeSe with temperature by means of high-resolution synchrotron powder X-ray diffraction. In the orthorhombic phase, the evolution of the bond distances with temperature is shown to deviate significantly with respect to SnSe. Analysis of the chemical bonding within the Quantum Theory of Atoms in Molecules shows that GeSe is ionic with van der Waals interlayer interactions...
April 25, 2017: Chemistry: a European Journal
R Furukawa, Y Unno, T Miura, A Yunoki, M Hachinohe, S Hamamatsu, H Itadzu, M Mizui
In Japan, we conducted proficiency testing of activity measurement by using high-purity germanium detectors for (134)Cs and (137)Cs in brown rice grains. Among 176 reported results, 86 % (for (134)Cs) and 93 % (for (137)Cs) of the results satisfied |En| ≦ 1. However, 58 reports for (134)Cs and 51 reports for (137)Cs had some failures in their evaluations of uncertainties. The proficiency testing was effective to improve the ability of uncertainty evaluation.
March 30, 2017: Applied Radiation and Isotopes
Muhammad Luthfi Bin Ismail, Fu-Quan Liu, Wai-Leung Yim, Rakesh Ganguly, Yongxin Li, Cheuk-Wai So
The reactivity of the 2-imino-5,6-methylenedioxylphenylgermanium(I) dimer toward group 9 metal(I) chloride and dimanganese decacarbonyl is described. [LGe:]2 (1, L = 2-imino-5,6-methylenedioxylphenyl) underwent a disproportionation reaction with 1.5 equiv of group 9 metal(I) chloride [MCl(cod)]2 (M = Rh, Ir) in toluene to afford a mixture of the group 9 metallogermylene-chlorometal(I) complexes [LGeμ-{M(cod)}2Cl] (M = Rh (2), Ir (4)) and chlorogermylene-chlorometal(I) complexes [L(Cl)GeM(cod)Cl] (M = Rh (3), Ir (5)), respectively...
April 20, 2017: Inorganic Chemistry
Alireza Kazemi, Sam Vaziri, Jorge Daniel Aguirre Morales, Sebastien Fregonese, Francesca Cavallo, Marziyeh Zamiri, Noel Mayur Dawson, Kateryna Artyushkova, Ying Bing Jiang, Steven R J Brueck, Sanjay Krishna
Heterostructures consisting of two-dimensional (2D) materials and conventional semiconductors have attracted a lot of attention due to their application in novel device concepts. In this work, we investigated the lateral transport characteristics of graphene/germanium heterostructures and compared it with the transport properties of graphene on SiO2. The heterostructures were fabricated by transferring a single layer graphene (Gr) onto lightly doped germanium (Ge) (100) substrate. The field effect measurements revealed a shift in the Dirac voltage of Gr on Ge substrates compared to the Gr on SiO2...
April 20, 2017: ACS Applied Materials & Interfaces
Hiroki Tanimoto, Junta Mori, Shunichiro Ito, Yasuhiro Nishiyama, Tsumoru Morimoto, Kazuo Tanaka, Yoshiki Chujo, Kiyomi Kakiuchi
This report describes the synthesis and characterization of arene-inserted type extended (ArEx) germa[N]pericyclynes composed of germanium and 1,4-diethynylbenzene units. These novel cyclic germanium-π unit materials were synthesized with diethynylbenzene and germanium dichloride. X-ray crystallographic analysis revealed their structures and the planar conformation of ArEx germa[4]pericyclyne along with the regulated aromatic rings. UV-vis absorption spectra and fluorescence emission spectra showed considerably unique and highly improved characters compared to previous germapericyclynes...
April 19, 2017: Chemistry: a European Journal
Wei Luo, Yunhui Gong, Yizhou Zhu, Yiju Li, Yonggang Yao, Ying Zhang, Kun Kelvin Fu, Glenn Pastel, Chuan-Fu Lin, Yifei Mo, Eric D Wachsman, Liangbing Hu
Substantial efforts are underway to develop all-solid-state Li batteries (SSLiBs) toward high safety, high power density, and high energy density. Garnet-structured solid-state electrolyte exhibits great promise for SSLiBs owing to its high Li-ion conductivity, wide potential window, and sufficient thermal/chemical stability. A major challenge of garnet is that the contact between the garnet and the Li-metal anodes is poor due to the rigidity of the garnet, which leads to limited active sites and large interfacial resistance...
April 18, 2017: Advanced Materials
Chaouki Siouani, Sofiane Mahtout, Sofiane Safer, Franck Rabilloud
We systematically study the equilibrium geometries, electronic and magnetic properties of Gen+1 and VGen (n = 1-19) clusters using the density functional theory approach (DFT) within the generalized gradient approximation (GGA). Endohedral structures in which the vanadium atom is encapsulated inside a Gen cage are predicted to be favored for n ≥ 10. The dopant V atom in the Gen clusters has not an immediate effect on the stability of small germanium clusters (n<6) but it largely contributes to strengthen the stability for n ≥ 7...
April 18, 2017: Journal of Physical Chemistry. A
M Hoshino, D Duflot, P Limão-Vieira, S Ohtomi, H Tanaka
Electron energy loss spectra of carbon tetrafluoride, silicon tetrafluoride, and germanium tetrafluoride molecules (CF4, SiF4, and GeF4) have been measured for incident electron energies of 50-360 eV at 1.5°-15.5° and for 30 eV and 30° scattering angle, while sweeping the energy loss over the range 9.0-20.0 eV. Low-lying valence excited triplet and singlet states are investigated by quantum chemical ab initio calculations. The Rydberg series converging to the (lowest) ionisation energy limits of XF4 (X = C, Si, Ge) are also identified and classified using the systematic behaviour according to the magnitude of the quantum defects...
April 14, 2017: Journal of Chemical Physics
Pavan Nukala, Mingliang Ren, Rahul Agarwal, Jacob Berger, Gerui Liu, A T Charlie Johnson, Ritesh Agarwal
Germanium telluride (GeTe) is both polar and metallic, an unusual combination of properties in any material system. The large concentration of free-carriers in GeTe precludes the coupling of external electric field with internal polarization, rendering it ineffective for conventional ferroelectric applications and polarization switching. Here we investigate alternate ways of coupling the polar domains in GeTe to external electrical stimuli through optical second harmonic generation polarimetry and in situ TEM electrical testing on single-crystalline GeTe nanowires...
April 12, 2017: Nature Communications
Stefan Wachter, Dmitry K Polyushkin, Ole Bethge, Thomas Mueller
The advent of microcomputers in the 1970s has dramatically changed our society. Since then, microprocessors have been made almost exclusively from silicon, but the ever-increasing demand for higher integration density and speed, lower power consumption and better integrability with everyday goods has prompted the search for alternatives. Germanium and III-V compound semiconductors are being considered promising candidates for future high-performance processor generations and chips based on thin-film plastic technology or carbon nanotubes could allow for embedding electronic intelligence into arbitrary objects for the Internet-of-Things...
April 11, 2017: Nature Communications
Morteza Javadi, Darren Picard, Regina Sinelnikov, Mary Alvean Narreto, Frank A Hegmann, Jonathan G C Veinot
The synthesis of germanium nanocrystals (GeNCs) with well-defined surface chemistry is of considerable interest because of their potential applications in the optoelectronic, battery, and semiconductor industries. Modifying and tailoring GeNC surface chemistry provides an avenue by which reactivity, environmental compatibility (e.g., solubility, resistance to oxidation), and electronic properties may be tailored. Hydride-terminated GeNCs (H-GeNCs) are of particular interest because the reactivity of surface Ge-H bonds toward alkenes and alkynes via hydrogermylation affords the potential for convenient modification; however, these reactions and their scope have not been widely explored...
April 19, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Yujin Ji, Mingye Yang, Huilong Dong, Tingjun Hou, Lu Wang, Youyong Li
Full utilization of solar energy to split water into hydrogen and oxygen is an efficient way to solve the current energy problem. Graphene-like germanium monochalcogenides (GeS or GeSe) are proposed here as efficient photocatalysts for water splitting under a broad range from ultraviolet, visible to near-infrared light dependent on their thickness. Compared to traditional photocatalysts, GeS and GeSe possess a large intrinsic dipole and introduce an internal electric field directing from Ge surface to S/Se surface, which causes notable band bending...
April 10, 2017: Nanoscale
Wei Sun, Grace Zhong, Christian Kübel, Abdinoor A Jelle, Chenxi Qian, Lu Wang, Manuchehr Ebrahimi, Laura M Reyes, Amr S Helmy, Geoffrey A Ozin
Germanium nanocrystals (ncGe) have not received as much attention as silicon nanocrystals (ncSi). However, Ge has demonstrated superiority over Si nanomaterials in some applications. Examples include, high charge-discharge rate lithium-ion batteries, small band-gap opto-electronic devices, and photo-therapeutics. When stabilized in an oxide matrix (ncGe/GeOx ), its high charge-retention has enabled non-volatile memories. It has also found utility as a high-capacity anode material for Li-ion batteries with impressive stability...
April 10, 2017: Angewandte Chemie
(no author information available yet)
Many extensions of the Standard Model of particle physics explain the dominance of matter over antimatter in our Universe by neutrinos being their own antiparticles. This would imply the existence of neutrinoless double-β decay, which is an extremely rare lepton-number-violating radioactive decay process whose detection requires the utmost background suppression. Among the programmes that aim to detect this decay, the GERDA Collaboration is searching for neutrinoless double-β decay of (76)Ge by operating bare detectors, made of germanium with an enriched (76)Ge fraction, in liquid argon...
April 5, 2017: Nature
Xuejun Xu, Hideaki Hashimoto, Kentarou Sawano, Takuya Maruizumi
We demonstrate germanium (Ge) microdisks surrounded by highly reflective circular Bragg gratings on highly n-doped germanium-on-insulator (GOI) substrate. The GOI substrate is fabricated by wafer bonding from Ge grown on Si substrate, and n-type doping concentration of 2.1×10<sup>19</sup> cm<sup>-3</sup> is achieved by phosphorus diffusion from a spin-on-dopant source. Very sharp Fabry-Perot resonant peaks with high contrast fringes and Q-factors up to 400 are observed near the direct band gap of Ge in photoluminescence spectra...
March 20, 2017: Optics Express
Jialin Jiang, Junqiang Sun, Yang Zhou, Jianfeng Gao, Heng Zhou, Ruiwen Zhang
We design a CMOS-compatible Distributed Bragg Reflector (DBR) laser based on highly uniaxial tensile stressed germanium. Our design first incorporates three critical elements including high uniaxial tensile stress, low loss optical resonator and heterojunction for electrical injection. A threshold current density of 80 kA/cm<sup>2</sup> and an internal quantum efficiency of 8.5% are estimated when the Shockley-Reed-Hall (SRH) lifetime is chosen to be 3 ns. Furthermore, the performance of the DBR laser can be enhanced by improving the crystal quality and carefully designing the p-n junction...
March 20, 2017: Optics Express
Meysam Najafi
The possibility of dichloroacetylene-sensing on carbon nanocone sheet and carbon germanium nanocone sheet surfaces has been investigated. The effects of nitrogen functionalization and dimethyl sulfoxide on the adsorption of dichloroacetylene gas on carbon nanocone sheet and carbon germanium nanocone sheet surfaces were investigated. Results reveal that adsorption of dichloroacetylene on studied nanocone sheets were exothermic. Results show that, adsorption energy value of dichloroacetylene on carbon germanium nanocone sheet surface were more negative than corresponding values of carbon nanocone sheet...
2017: Acta Chimica Slovenica
Xiaomei Ma, Yongning Zhou, Min Chen, Limin Wu
The development of environment-friendly and high-performance carbon materials for energy applications has remained a great challenge. Here, a novel and facile method for synthesis of olive-like nitrogen-doped carbon embedded with germanium (Ge) nanoparticles using widespread and nontoxic dopamine as carbon and nitrogen precursors is demonstrated, especially by understanding the tendency of pure GeO2 nanoparticles forming ellipsoidal aggregation, and the chelating reaction of the catechol structure in dopamine with metal ions...
April 3, 2017: Small
Yanchun Yin, Andrew Chew, Xiaoming Ren, Jie Li, Yang Wang, Yi Wu, Zenghu Chang
We present an approach for both efficient generation and amplification of 4-12 μm pulses by tailoring the phase matching of the nonlinear crystal Zinc Germanium Phosphide (ZGP) in a narrowband-pumped optical parametric chirped pulse amplifier (OPCPA) and a broadband-pumped dual-chirped optical parametric amplifier (DC-OPA), respectively. Preliminary experimental results are obtained for generating 1.8-4.2 μm super broadband spectra, which can be used to seed both the signal of the OPCPA and the pump of the DC-OPA...
April 3, 2017: Scientific Reports
Alexander Winkler, Hanna Koivunoro, Sauli Savolainen
The next step in the boron neutron capture therapy (BNCT) is the real time imaging of the boron concentration in healthy and tumor tissue. Monte Carlo simulations are employed to predict the detector response required to realize single-photon emission computed tomography in BNCT, but have failed to correctly resemble measured data for cadmium telluride detectors. In this study we have tested the gamma production cross-section data tables of commonly used libraries in the Monte Carlo code MCNP in comparison to measurements...
March 27, 2017: Applied Radiation and Isotopes
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"