Temperature-dependent valence bond structure study of tantalum

2007 ◽  
Vol 393 (1-2) ◽  
pp. 119-124 ◽  
Author(s):  
Li Xiaobo ◽  
Xie Youqing ◽  
Nie Yaozhuang ◽  
Peng Hongjian
Keyword(s):  
Valence Bond ◽  
Structure Study ◽  
Temperature Dependent ◽  
Valence Bond Structure

A study of temperature-dependent valence bond structure of titanium

2007 ◽  
Vol 20 (1) ◽  
pp. 27-34
Author(s):  
X LI ◽  
Y XIE ◽  
Y NIE ◽  
H PENG ◽  
H TAO ◽  
...  
Keyword(s):  
Valence Bond ◽  
Temperature Dependent ◽  
Valence Bond Structure

Valence Bond Structure and Mechanical Properties of CNxFilms Prepared by Glow Discharge Assisted Pulsed Laser Deposition

2013 ◽  
Vol 40 (11) ◽  
pp. 1107002
Author(s):  
郑晓华 Zheng Xiaohua ◽  
宋建强 Song Jianqiang ◽  
杨芳儿 Yang Fanger ◽  
陈占领 Chen Zhanling
Keyword(s):  
Mechanical Properties ◽  
Glow Discharge ◽  
Pulsed Laser Deposition ◽  
Valence Bond ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Valence Bond Structure

A temperature-dependent structure study of gem-quality hibonite from Myanmar

2010 ◽  
Vol 74 (5) ◽  
pp. 871-885 ◽  
Author(s):  
M. Nagashima ◽  
T. Armbruster ◽  
T. Hainschwang
Keyword(s):  
Room Temperature ◽  
Structure Study ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Trigonal Bipyramidal ◽  
Expansion Coefficients ◽  
Increasing Temperature ◽  
Length Distortion

AbstractThe structure of hibonite from Myanmar (space group P63/mmc, Z = 2, at room temperature a = 5.5909(1), c = 21.9893(4) Å), with simplified formula CaAl12O19 and composition (Ca0.99Na0.01)Σ1.00 was investigated between temperatures of 100 K and 923 K by single-crystal X-ray diffraction methods. Structure refinements have been performed at 100, 296, 473 and 923 K. In hibonite from Myanmar, Ti substitutes for Al mainly at the octahedral Al4 site and, to a lesser degree, at the trigonal bipyramidal site, Al2. The Al4 octahedra build face-sharing dimers. If Ti4+ substitutes at Al4, adjacent cations repulse each other for electrostatic reasons, leading to off-centre cation displacement associated with significant bond-length distortion compared to synthetic (Ti-free) CaAl12O19. Most Mg and smaller proportions of Zn and Si are assigned to the tetrahedral Al3 site. 12-coordinated Ca in hibonite replaces oxygen in a closest-packed layer. However, Ca is actually too small for this site and engages in a ‘rattling-type’ motion with increasing temperature. For this reason, Ca does not significantly increase thermal expansion coefficients of hibonite. The expansion of natural Ti,Mg-rich hibonite between 296 and 923 K along the x and the z axes is αa = 7.64×10–6 K–1 and αc = 11.19×10–6 K–1, respectively, and is thus very similar to isotypic, synthetic CaAl12O19 and LaMgAl11O19 (LMA).

Thermally driven V2O5nanocrystal formation and the temperature-dependent electronic structure study

CrystEngComm ◽  
2012 ◽  
Vol 14 (2) ◽  
pp. 626-631 ◽  
Author(s):  
Chongwen Zou ◽  
Lele Fan ◽  
Ruiqun Chen ◽  
Xiaodong Yan ◽  
Wensheng Yan ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Structure Study ◽  
Temperature Dependent ◽  
Thermally Driven

scholarly journals Graphene Nanoribbon Conductance Model in Parabolic Band Structure

2010 ◽  
Vol 2010 ◽  
pp. 1-4 ◽  
Author(s):  
Mohammad Taghi Ahmadi ◽  
Zaharah Johari ◽  
N. Aziziah Amin ◽  
Amir Hossein Fallahpour ◽  
Razali Ismail
Keyword(s):  
Band Structure ◽  
Quantum Confinement Effect ◽  
Structure Study ◽  
Graphene Nanoribbon ◽  
Published Data ◽  
Temperature Dependent ◽  
Charge Neutrality ◽  
Base Method ◽  
Long Channel ◽  
Neutrality Point

Many experimental measurements have been done on GNR conductance. In this paper, analytical model of GNR conductance is presented. Moreover, comparison with published data which illustrates good agreement between them is studied. Conductance of GNR as a one-dimensional device channel with parabolic band structures near the charge neutrality point is improved. Based on quantum confinement effect, the conductance of GNR in parabolic part of the band structure, also the temperature-dependent conductance which displays minimum conductance near the charge neutrality point are calculated. Graphene nanoribbon (GNR) with parabolic band structure near the minimum band energy terminates Fermi-Dirac integral base method on band structure study. While band structure is parabola, semiconducting GNRs conductance is a function of Fermi-Dirac integral which is based on Maxwell approximation in nondegenerate limit especially for a long channel.

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