Synthesis of Thin Cr3Se4Films from Modulated Elemental Reactants via Two Amorphous Intermediates:  A Detailed Examination of the Reaction Mechanism

2006 ◽  
Vol 45 (6) ◽  
pp. 2704-2712 ◽  
Author(s):  
Malte Behrens ◽  
Ragnar Kiebach ◽  
Wolfgang Bensch ◽  
Dietrich Häussler ◽  
Wolfgang Jäger
Keyword(s):  
Reaction Mechanism ◽  
Detailed Examination ◽  
Modulated Elemental Reactants ◽  
Elemental Reactants

scholarly journals Characterization of Cr-rich Cr-Sb multilayer films: Syntheses of a new metastable phase using modulated elemental reactants

2015 ◽  
Vol 230 ◽  
pp. 254-265 ◽  
Author(s):  
Matthias Regus ◽  
Sergiy Mankovsky ◽  
Svitlana Polesya ◽  
Gerhard Kuhn ◽  
Jeffrey Ditto ◽  
...  
Keyword(s):  
Metastable Phase ◽  
Multilayer Films ◽  
Modulated Elemental Reactants ◽  
Elemental Reactants

Topological insulator bismuth selenide grown on black phosphorus for sensitive broadband photodetection

2021 ◽  
Author(s):  
Dae-Kyoung Kim ◽  
Seok-Bo Hong ◽  
Jonghoon Kim ◽  
Mann-Ho Cho
Keyword(s):  
Topological Insulator ◽  
Black Phosphorus ◽  
Bismuth Selenide ◽  
High Quality ◽  
Modulated Elemental Reactants ◽  
Elemental Reactants

We investigate a high-quality Bi2Se3/black phosphorus (BP) heterostructure prepared through the modulated elemental reactants (MER, annealed in situ at 220 °C for 20 min under a vacuum of 10−9 Torr)...

Preparation of (TiTe2)x(Sb2Te3)y(TiTe2)3(Bi2Te3)z Superlattices using the Modulated Elemental Reactants (MER) Technique

2005 ◽  
Vol 886 ◽  
Author(s):  
Clay Mortensen ◽  
Ben Matelich ◽  
Benjamin Schmid ◽  
Raimar Rostek ◽  
David C. Johnson
Keyword(s):  
Annealing Temperature ◽  
Unit Cell ◽  
Good Reproducibility ◽  
Cell Control ◽  
Depth Profiles ◽  
Modulated Elemental Reactants ◽  
Tof Sims ◽  
Elemental Reactants

AbstractDifficulty in preparing (Bi2Te3)x(Sb2Te3)y superlattices due to interdiffusion of Sb and Bi led to the study of interduffusion barriers. TiTe2 has been explored as an interdiffusion barrier to minimize the interdiffusion of Sb and Bi, as TiTe2 is not soluble in either Bi2Te3 or Sb2Te3. Preparation of (TiTe2)3(Sb2Te3)y(TiTe2)3(Bi2Te3)z superlattices has been achieved with varying x, y and z. The formation of the superlattices was studied as a function of annealing temperature and time. TOF-SIMS depth profiles were used to study the extent of interdiffusion in the samples. Unit cell control was achieved allowing for the preparation of an array of superlattices with varying periods with very good reproducibility.

Synthesis of New Thermoelectrics Using Modulated Elemental Reactants

1997 ◽  
Vol 478 ◽  
Author(s):  
Marc D. Hornbostel ◽  
Heike Sellinschegg ◽  
David C. Johnson
Keyword(s):  
Crystal Structure ◽  
X Ray Diffraction ◽  
Systematic Screening ◽  
X Ray ◽  
Low Temperature Annealing ◽  
Modulated Elemental Reactants ◽  
Ternary Metal ◽  
Elemental Reactants ◽  
Binary Compounds ◽  
New Compounds

AbstractA series of new, metastable ternary crystalline compounds with the skutterudite crystal structure have been synthesized using modulated elemental reactants. The initial reactants are made up of multiple repeats of a ˜25Å thick unit containing elemental layers of the desired ternary metal, iron and antimony. Low temperature annealing (150°C) results in interdiffusion of the elemental layers to form amorphous reaction intermediates. Annealing these intermediates at temperatures between 200°C and 250°C results in exothermic crystallization of the desired skutterudite crystal structure. Most of the new compounds prepared are only kinetically stable, decomposing exothermically to form thermodynamically more stable mixtures of binary compounds and elements. Low angle x-ray diffraction studies show that the resulting films are exceedingly smooth. These films have an ideal geometry for measuring properties of importance for thermoelectric devices—the Seebeck coefficient and the electrical conductivity. Thermal conductivity can be measured using a modification of the 3ω technique of Cahill. Samples can be produced rapidly, allowing for systematic screening and subsequent optimization as a function of composition and doping levels.

ChemInform Abstract: Low Temperature Synthesis Using Modulated Elemental Reactants: A New Metastable Ternary Compound, NixMoSe2.

ChemInform ◽  
2010 ◽  
Vol 33 (36) ◽  
pp. no-no
Author(s):  
Polly A. Berseth ◽  
Thomas A. Hughes ◽  
Robert Schneidmiller ◽  
Arwyn Smalley ◽  
David C. Johnson
Keyword(s):  
Low Temperature ◽  
Ternary Compound ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Modulated Elemental Reactants ◽  
Elemental Reactants

Calorimetric study of the nucleation of LaxCo4Sb12 prepared from modulated elemental reactants

2002 ◽  
Vol 388 (1-2) ◽  
pp. 151-158 ◽  
Author(s):  
Gene Yoon ◽  
Heike Sellinschegg ◽  
David C. Johnson
Keyword(s):  
Calorimetric Study ◽  
Modulated Elemental Reactants ◽  
Elemental Reactants

The Preparation of Crystalline NbSe2/TiSe2 Superlattices from Modulated Elemental Reactants

1995 ◽  
Vol 382 ◽  
Author(s):  
Myungkeun Noh ◽  
James Thiel ◽  
David C. Johnson
Keyword(s):  
Diffraction Data ◽  
Substrate Surface ◽  
Domain Size ◽  
High Angle ◽  
High Quality ◽  
Rocking Curve ◽  
Modulated Elemental Reactants ◽  
Unit Cells ◽  
Controlled Crystallization ◽  
Elemental Reactants

ABSTRACTThree new crystalline NbSe2/TiSe2 superlattice compounds with 43.472±0.005A, 80.66±0.03A and 117.9±0.1Å unit cells in thec direction were prepared through controlled crystallization of Ti/Se/Nb/Se superlattice reactants with different compositional layer thicknesses. Theta-theta and rocking curve data were collected using a theta-theta diffractometer to study the evolution of the initially layered reactants into the crystalline superlattices as a function of temperature. Low angle diffraction data demonstrates that the initial layered reactant contracts in the c-axis direction upon initial annealing and suggests that the interfaces become smoother during this initial interdiffusion. High angle rocking curve diffraction data shows the development of caxis oriented NbSe2fTiSe2 crystal growth perpendicular to the substrate surface. Theta-theta scans show a gradual decrease of the (001) diffraction linewidths of the growing compound as a function of annealing time and temperature indicating an increase in the c-axis domain size. High quality caxis oriented TiSe2/NbSe2 crystalline superlattices result from annealing at the relatively low temperature of 500ºC. The rational synthesis of intergrowth compounds from superlattice reactants as described herein will permit the tailoring of physical properties as a function of compositional layer thicknesses and nativeproperties of the parent compounds.

The Preparation of Kinetically Stable Crystalline Compounds from Modulated Elemental Reactants

1996 ◽  
Vol 453 ◽  
Author(s):  
Marc D. Hornbostel ◽  
Myungkeun Noh ◽  
Christopher D. Johnson ◽  
David C. Johnson
Keyword(s):  
Transition Metal ◽  
Three Dimensions ◽  
Transition Metal Dichalcogenide ◽  
Initial Reactant ◽  
Compositional Modulation ◽  
Modulated Elemental Reactants ◽  
Annealing Conditions ◽  
Temperature Diffusion ◽  
Metastable Compounds ◽  
Elemental Reactants

AbstractDiffusion distances within elementally modulated reactants can be controlled on an Angstrom length scale. Below a critical repeat thickness, elementally modulated reactants interdiffuse without nucleating crystalline compounds. Using this amorphous intermediate, we can prepare metastable compounds by controlling nucleation: Above this critical repeat thickness, crystalline compounds nucleate at the reacting interfaces. Using the architecture of the initial reactant to control the diffusion distances in the initial reactant, we have found that we can prepare crystalline superlattices. Crystalline superlattice compounds containing integral numbers of inter grown transition metal dichalcogenide layers and alternating layers of transition metal carbides have been prepared through controlled crystallization of superlattice reactants with designed compositional modulation. High quality c-axis oriented dichalcogenide crystalline superlattices result from extended annealing at relatively low temperatures. A large number of [00l] diffraction orders and off-axis [10l] diffraction peaks are observed indicating that these compounds are crystalline in three dimensions. Similar annealing conditions were used to prepare carbide superlattices, however the limited low temperature diffusion rates of the carbides limit the crystallite size to approximately 300Å. The rational synthesis of these intergrowth compounds from superlattice reactants permits the exploratory synthesis of a new class of compounds and the tailoring of physical properties as a function of compositional layer thicknesses and native properties of the parent compounds.

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