Spontaneous growth of hexagonal ZrB2 nanoplates driven by a screw dislocation mechanism

CrystEngComm ◽  
2018 ◽  
Vol 20 (47) ◽  
pp. 7637-7641 ◽  
Author(s):  
Da Liu ◽  
Yanhui Chu ◽  
Beilin Ye ◽  
Xiya Zhou
Keyword(s):  
Molten Salt ◽  
Screw Dislocation ◽  
Growth Mechanism ◽  
Reduction Technique ◽  
Dislocation Mechanism ◽  
Spontaneous Growth ◽  
Borothermal Reduction ◽  
First Time

Hexagonal ZrB2 nanoplates had been successfully synthesized by a facile molten-salt assisted borothermal reduction technique based on the screw dislocation growth mechanism for the first time.

MOLTEN SALT SYNTHESIS OF YF3:Yb3+/Ln3+(Ln = Er3+, Tm3+) MICROSHEETS WITH MULTICOLOR UPCONVERSION LUMINESCENCE

2013 ◽  
Vol 06 (06) ◽  
pp. 1350061 ◽  
Author(s):  
MINGYE DING ◽  
CHUNHUA LU ◽  
LINHAI CAO ◽  
YARU NI ◽  
ZHONGZI XU
Keyword(s):  
Molten Salt ◽  
Laser Diode ◽  
Upconversion Luminescence ◽  
Emission Spectra ◽  
Upconversion Emission ◽  
Molten Salt Synthesis ◽  
Molten Salt Method ◽  
Orthorhombic System ◽  
Co Doping ◽  
First Time

In this paper, highly crystalline YF 3: Yb 3+/ Ln 3+( Ln = Er 3+, Tm 3+) microsheets were successfully synthesized by a surfactant-free molten salt method for the first time. The results indicated that the as-obtained samples belonged to orthorhombic system and exhibited microsheets morphology with side lengths of 30 to 80 μm and wall thickness from 1 to 1.5 μm. By changing the dopant's species ( Ln 3+), multicolor (yellow and blue) upconversion emission can be observed in YF 3: Yb 3+/ Ln 3+ microsheets under 980 nm laser diode (LD) excitation. The upconversion mechanisms in co-doping YF 3 samples were analyzed in detail based on the emission spectra. Importantly, this approach not only proposes a new alternative in synthesizing such materials, but also opens the possibility to meet the increasing commercial demand.

scholarly journals A preliminary investigation of the molten salt mediated synthesis of Gd2TiO5 ‘stuffed’ pyrochlore

MRS Advances ◽  
2021 ◽  
Author(s):  
D. A. Austin ◽  
M. Cole ◽  
M. C. Stennett ◽  
C. L. Corkhill ◽  
N. C. Hyatt
Keyword(s):  
Molten Salt ◽  
Single Phase ◽  
Preliminary Investigation ◽  
Pyrochlore Phase ◽  
Comparative Investigation ◽  
Molten Salt Synthesis ◽  
Control Rods ◽  
First Time ◽  
Conventional Solid State Synthesis ◽  
Nuclear Applications

Abstract Refractory ‘stuffed’ pyrochlores such as Gd2TiO5 are of interest for nuclear applications, including as matrices for actinide disposition and as neutron absorbers in control rods. Here, we report the results of a preliminary comparative investigation of the synthesis of Gd2TiO5 by molten salt and conventional solid-state synthesis. We show that synthesis of Gd2TiO5 proceeds from the pyrochlore phase Gd2Ti2O7 which is first formed as a kinetic product. Molten salt synthesis afforded single phase Gd2TiO5 at 1300 °C in 2 h, via a template growth mechanism, and is effective for the synthesis of these refractory materials. This work demonstrates molten salt mediated synthesis of ‘stuffed’ pyrochlore for the first time. Graphic abstract

scholarly journals Li–Yorke Chaos in Hybrid Systems on a Time Scale

2015 ◽  
Vol 25 (14) ◽  
pp. 1540024 ◽  
Author(s):  
Marat Akhmet ◽  
Mehmet Onur Fen
Keyword(s):  
Differential Equations ◽  
Hybrid Systems ◽  
Time Scales ◽  
Time Scale ◽  
Impulsive Differential Equations ◽  
Reduction Technique ◽  
Duffing Equation ◽  
Dynamic Equations ◽  
Definition Of ◽  
First Time

By using the reduction technique to impulsive differential equations [Akhmet & Turan, 2006], we rigorously prove the presence of chaos in dynamic equations on time scales (DETS). The results of the present study are based on the Li–Yorke definition of chaos. This is the first time in the literature that chaos is obtained for DETS. An illustrative example is presented by means of a Duffing equation on a time scale.

Threading Screw Dislocations in a Two-Phase Plate and a Two-Phase Sphere

2018 ◽  
Vol 55 (1) ◽  
pp. 102-116 ◽  
Author(s):  
A.L. Kolesnikova ◽  
M.Yu. Gutkin ◽  
A.E. Romanov
Keyword(s):  
Screw Dislocation ◽  
Hollow Sphere ◽  
Phase Plate ◽  
Stress Distributions ◽  
Two Phase ◽  
Parallel Edge ◽  
Free Surfaces ◽  
Shear Moduli ◽  
Elastic Fields ◽  
First Time

Abstract A screw dislocation perpendicular to free surfaces and an interface in a two-phase plate, and a screw dislocation piercing a two-phase hollow sphere are considered. The analytical solutions of the boundary-value problems have been found for the first time with the help of the virtual defects technique. Elastic fields of the screw dislocation in the plate are presented in the form of integrals with Bessel functions. Elastic fields of the screw dislocation in the hollow sphere have the form of series with Legendre polynomials. Stress distributions in both of the considered geometries are plotted. The influence of the geometric parameters of the considered solids and the ratio of the shear moduli on the stresses is analyzed. The interaction of a screw dislocation with a parallel edge dislocation is discussed.

Preparation and Characterization of Calcium Titanate (CaTiO3) Whiskers via Molten Salt Method

2012 ◽  
Vol 630 ◽  
pp. 89-92
Author(s):  
Yong Xing Zhang ◽  
Xue Ying Nai ◽  
Ming Wei ◽  
Dong Hai Zhu ◽  
Cheng Cai Zhu ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Single Crystal ◽  
Molten Salt ◽  
Calcium Chloride ◽  
Growth Mechanism ◽  
Calcium Titanate ◽  
Reaction Process ◽  
Molten Salt Method ◽  
Optimum Synthesis

Well dispersive and single crystal calcium titanate (CaTiO3) whisker with a length of 50-100μm was synthesized by sintering the mixture of calcium chloride and titanium dioxide with improvement of adding the mineralization agent of Pb(Ac)2.3H2O. The as-prepared samples were characterized by XRD, SEM. The optimum synthesis condition and the effect of the mineralization agent were discussed respectively. In the end, the possible reaction process was given and a LS growth mechanism was proposed.

scholarly journals Preliminary study on the growth mechanism of zircon whiskers prepared via non-hydrolytic sol-gel method combined with carbon black as reducing agent

2018 ◽  
Vol 12 (2) ◽  
pp. 95-99
Author(s):  
Guo Feng ◽  
Feng Jiang ◽  
Weihui Jiang ◽  
Jianmin Liu ◽  
Sanhai Wang ◽  
...  
Keyword(s):  
Carbon Black ◽  
Growth Mechanism ◽  
Sol Gel ◽  
Zircon Crystal ◽  
Reducing Agent ◽  
Dislocation Mechanism ◽  
Gel Method ◽  
Sol Gel Method ◽  
Crystal Particle ◽  
Axial Growth

Zircon whiskers were prepared at 700?C via non-hydrolytic sol-gel method combined with carbon black as reducing agent, Si(OC2H5)4 (TEOS) and ZrCl4 as precursors and LiF as mineralizer. The whiskers were characterized and their growth mechanism was discussed. The results show that the introduction of carbon black is beneficial for the preferential axial growth of zircon crystals into whiskers. The diameter and aspect ratio of zircon whiskers are 30-40 nm and 6-15, respectively. The zircon whiskers grow along the [001] direction, which is c-axis oriented. The growth mechanism is revealed to be the screw dislocation mechanism with the mass transport mainly from the zircon crystal particle matrix.

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