First-Principles Combinatorial Design of Transition Temperatures in Multicomponent Systems: The Case of Mn in GaAs

2006 ◽  
Vol 97 (4) ◽  
Author(s):  
A. Franceschetti ◽  
S. V. Dudiy ◽  
S. V. Barabash ◽  
A. Zunger ◽  
J. Xu ◽  
...  
Keyword(s):  
First Principles ◽  
Combinatorial Design ◽  
Multicomponent Systems ◽  
Transition Temperatures

Thermal Properties and Transition Temperatures of AlB2-Type Diborides

2015 ◽  
Vol 817 ◽  
pp. 740-747
Author(s):  
Ming Jun Peng ◽  
Yong Hua Duan ◽  
Yong Sun
Keyword(s):  
Thermal Properties ◽  
Bulk Modulus ◽  
Melting Temperature ◽  
First Principles ◽  
Transition Temperatures ◽  
Coupling Constant ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
The Relationship ◽  
Theoretical Results

The thermal properties, cohesion and transition temperatures of 14 compounds in the AlB2-type diborides have been calculated by first-principles. The obtained thermal properties, cohesion and transition temperatures Tc were compared with both available experimental data and other theoretical results. The relationship among enthalpy formation, bulk modulus and melting temperature in these diborides were further analyzed. The results illustrate that ZrB2 is the most stable, and AuB2 has the largest c/a ratio and it is also most unstable to a phase separation. It is observed that the diborides including Mg, Sc, and Hf series with a more negative enthalpy of formation have a larger bulk modulus and higher melting temperature. AuB2 has higher electron-phonon coupling constant and hence possesses a higher Tc.

Theoretical Investigation of Fe-Based Phase Equilibria from the First-Principles

2005 ◽  
Vol 475-479 ◽  
pp. 3127-3130 ◽  
Author(s):  
Ying Chen ◽  
Shuichi Iwata ◽  
Tetsuo Mohri
Keyword(s):  
Theoretical Investigation ◽  
Phase Stability ◽  
First Principles ◽  
Cluster Variation Method ◽  
High Accuracy ◽  
Variation Method ◽  
Transition Temperatures ◽  
Spin Polarized ◽  
Cluster Variation ◽  
Effective Cluster

Theoretical investigation of the phase equilibira of three kinds of Fe-based alloys, Fe-Ni, Fe-Pd and Fe-Pt systems is attempted by combining FLAPW total energy calculations and Cluster Variation Method. It is revealed that the magnetism plays a crucial role in the phase stability and spin polarized calculation is indispensable. The experimental L10-disorder transition temperatures are reproduced with fairly high accuracy. Thermal vibration effects incorporated based on the Debye-Gruneisen model further improve the calculated transition temperatures. Furthermore, the influence of the various effective cluster interactions on phase stability is calculated systematically.

A standard for transmission electron spectroscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 530-531 ◽  
Author(s):  
Dennis Maher ◽  
David Joy ◽  
Peggy Mochel
Keyword(s):  
Thin Films ◽  
Electron Spectroscopy ◽  
Host Lattice ◽  
Single Element ◽  
Multicomponent Systems ◽  
Transmission Electron ◽  
Major Interest ◽  
Standard Specimens ◽  
Forms Of Carbon ◽  
Electron Energy Loss

A variety of standard specimens is needed in order to systematically investigate the instrumentation, specimen, data reduction and quantitation variables in electron energy-loss spectroscopy (EELS). Pure single element specimens (e.g. various forms of carbon) have received considerable attention to date but certain elements of interest cannot be prepared directly as thin films. Since studies of the first and second row elements in two- or multicomponent systems will be of considerable importance in microanalysis using EELS, there is a need for convenient standards containing these species. For many investigations a standard should contain the desired element, or elements, homogeneously dispersed through a suitable matrix and at an accurately known concentration. These conditions may be met by the technique of implantation.Silicon was chosen as the host lattice since its principal ionization energies, EL23 = 98 eV and Ek = 1843 eV, are well removed from the K-edges of most elements of major interest such as boron (Ek = 188 eV), carbon (Ek = 283 eV), nitrogen (Ek = 400 eV) and oxygen (Ek = 532 eV).

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