نتایج جستجو برای: hafnium

تعداد نتایج: 1994  

Journal: :The Journal of chemical physics 2012
Xiang Li Weijun Zheng Angela Buonaugurio Allyson Buytendyk Kit Bowen Krishnan Balasubramanian

Negative ion photoelectron spectra of ZrO(-), HfO(-), HfHO(-), and HfO(2)H(-) are reported. Even though zirconium- and hafnium-containing molecules typically exhibit similar chemistries, the negative ion photoelectron spectral profiles of ZrO(-) and HfO(-) are dramatically different from one another. By comparing these data with relevant theoretical and experimental studies, as well as by using...

Journal: :Chemical communications 2013
Michael J Sgro Douglas W Stephan

Hf-phosphinoamide cation complexes behave as metal-based frustrated Lewis pairs and bind one or two equivalent of CO2 and in as well can activate CO2 in a bimetallic fashion to give a pseudo-tetrahedral P2CO2 fragment linking two Hf centres.

2010
J. Augustinus Viljoen Hendrik G. Visser Andreas Roodt

In the title compound, [Hf(C(15)H(11)O(2))(4)], the Hf(IV) atom is coordinated by four 1,3-diphenyl-propane-1,3-dionato ligands with an average Hf-O distance of 2.17 (3) Å and O-Hf-O bite angles varying from 74.5 (1) to 75.02 (9)°. The coordination polyhedron shows a slightly distorted Archimedean square-anti-prismatic geometry. The crystal packing is stabilized by weak C-H⋯O inter-actions.

2014
Yung-Yu Chen

The channel fluorine implantation (CFI) process was integrated with the Si₃N₄ contact etch stop layer (SiN CESL) uniaxial-strained n-channel metal-oxide-semiconductor field-effect transistor (nMOSFET) with the hafnium oxide/silicon oxynitride (HfO₂/SiON) gate stack. The SiN CESL process clearly improves basic electrical performance, due to induced uniaxial tensile strain within the channel. How...

Journal: :Physical chemistry chemical physics : PCCP 2017
Fei Huang Xing Chen Xiao Liang Jun Qin Yan Zhang Taixing Huang Zhuo Wang Bo Peng Peiheng Zhou Haipeng Lu Li Zhang Longjiang Deng Ming Liu Qi Liu He Tian Lei Bi

Owing to their prominent stability and CMOS compatibility, HfO2-based ferroelectric films have attracted great attention as promising candidates for ferroelectric random-access memory applications. A major reliability issue for HfO2 based ferroelectric devices is fatigue. So far, there have been a few studies on the fatigue mechanism of this material. Here, we report a systematic study of the f...

Journal: :The Journal of chemical physics 2006
P Havu V Havu M J Puska M H Hakala A S Foster R M Nieminen

We have modeled transport properties of nanostructures using Green's-function method within the framework of the density-functional theory. The scheme is computationally demanding, so numerical methods have to be chosen carefully. A typical solution to the numerical burden is to use a special basis-function set, which is tailored to the problem in question, for example, the atomic-orbital basis...

2013
Lauren B. Raine Hyun Kyu Lee Brian J. Saliba Laura Chaddock-Heyman Charles H. Hillman Arthur F. Kramer

INTRODUCTION There is a growing trend of inactivity among children, which may not only result in poorer physical health, but also poorer cognitive health. Previous research has shown that lower fitness has been related to decreased cognitive function for tasks requiring perception, memory, and cognitive control as well as lower academic achievement. PURPOSE To investigate the relationship bet...

Journal: :Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada 2014
Désirée Viladot Joaquim Portillo Mauro Gemí Stavros Nicolopoulos Núria Llorca-Isern

The structure determination of an HfSi4 precipitate has been carried out by a combination of two precession electron diffraction techniques: high precession angle, 2.2°, single pattern collection at eight different zone axes and low precession angle, 0.5°, serial collection of patterns obtained by increasing tilts of 1°. A three-dimensional reconstruction of the associated reciprocal space show...

2017
Matthew J Cliffe Elizabeth Castillo-Martínez Yue Wu Jeongjae Lee Alexander C Forse Francesca C N Firth Peyman Z Moghadam David Fairen-Jimenez Michael W Gaultois Joshua A Hill Oxana V Magdysyuk Ben Slater Andrew L Goodwin Clare P Grey

We report a hafnium-containing MOF, hcp UiO-67(Hf), which is a ligand-deficient layered analogue of the face-centered cubic fcu UiO-67(Hf). hcp UiO-67 accommodates its lower ligand:metal ratio compared to fcu UiO-67 through a new structural mechanism: the formation of a condensed "double cluster" (Hf12O8(OH)14), analogous to the condensation of coordination polyhedra in oxide frameworks. In oxi...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید