The Synthesis of [(Bi2Te3)x{(TiTe2)y}1.36] Superlattices from Modulated Elemental Reactants

2005 ◽  
Vol 127 (21) ◽  
pp. 7843-7848 ◽  
Author(s):  
Fred R. Harris ◽  
Stacey Standridge ◽  
David C. Johnson
2015 ◽  
Vol 230 ◽  
pp. 254-265 ◽  
Author(s):  
Matthias Regus ◽  
Sergiy Mankovsky ◽  
Svitlana Polesya ◽  
Gerhard Kuhn ◽  
Jeffrey Ditto ◽  
...  

Author(s):  
Dae-Kyoung Kim ◽  
Seok-Bo Hong ◽  
Jonghoon Kim ◽  
Mann-Ho Cho

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)...


2005 ◽  
Vol 886 ◽  
Author(s):  
Clay Mortensen ◽  
Ben Matelich ◽  
Benjamin Schmid ◽  
Raimar Rostek ◽  
David C. Johnson

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.


2006 ◽  
Vol 45 (6) ◽  
pp. 2704-2712 ◽  
Author(s):  
Malte Behrens ◽  
Ragnar Kiebach ◽  
Wolfgang Bensch ◽  
Dietrich Häussler ◽  
Wolfgang Jäger

1997 ◽  
Vol 478 ◽  
Author(s):  
Marc D. Hornbostel ◽  
Heike Sellinschegg ◽  
David C. Johnson

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 ◽  
2010 ◽  
Vol 33 (36) ◽  
pp. no-no
Author(s):  
Polly A. Berseth ◽  
Thomas A. Hughes ◽  
Robert Schneidmiller ◽  
Arwyn Smalley ◽  
David C. Johnson

2002 ◽  
Vol 388 (1-2) ◽  
pp. 151-158 ◽  
Author(s):  
Gene Yoon ◽  
Heike Sellinschegg ◽  
David C. Johnson

1995 ◽  
Vol 382 ◽  
Author(s):  
Myungkeun Noh ◽  
James Thiel ◽  
David C. Johnson

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.


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