Co effect on zinc blende–rocksalt phase transition in CdS nanocrystals

RSC Advances ◽  
2015 ◽  
Vol 5 (23) ◽  
pp. 17582-17587 ◽  
Author(s):  
Rui Zhao ◽  
Pan Wang ◽  
Bin-bin Yao ◽  
Ting-ting Hu ◽  
Tian-ye Yang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Bulk Modulus ◽  
Cds Nanocrystals ◽  
Zinc Blende ◽  
Rocksalt Phase

The Co dopant significantly promotes the zinc blende to rocksalt phase transition and increases the bulk modulus compared with CdS nanocrystals.

InP under high pressures

1992 ◽  
Vol 7 (8) ◽  
pp. 2205-2210 ◽  
Author(s):  
M-H. Tsai ◽  
John D. Dow ◽  
R.V. Kasowski
Keyword(s):  
Phase Transition ◽  
Bulk Modulus ◽  
High Pressures ◽  
Linear Functions ◽  
Rocksalt Structure ◽  
Zinc Blende ◽  
Direct Energy ◽  
Photoluminescence Studies ◽  
Calculated Bond Length ◽  
Good Agreement

The direct energy gaps, Eg, and the indirect gaps at the X point, E(X), of GaAs and AlxGa1−xAs alloys are essentially linear functions of hydrostatic pressure, P. Recent photoluminescence measurements of Tozer et al. for InP under high pressures, however, found that Eg(P) is not quite linear, but bends down slightly at high pressures. Using the first-principles pseudofunction method, we have calculated Eg and E(X) as functions of pressure, as well as the zero-temperature equation of state P(V). Our calculated gap curve for InP, Eg(P), bends down slightly, as found in photoluminescence studies. The slope dEg/dP is 8.8 meV/kbar for small pressures P, and is in good agreement with the experimental value, 8.32 meV/kbar. The observed nonlinearity in the dependence of Eg on pressure for InP is attributed to a large derivative of the bulk modulus with respect to pressure. The calculated bond length, bulk modulus, and critical pressure for a phase transition from the zinc blende to a rocksalt structure, and the unit cell volume change at this phase transition are all in good agreement with the data.

First-principles study of zinc-blende to rocksalt phase transition in BP and BAs

2009 ◽  
Vol 44 (4) ◽  
pp. 1386-1389 ◽  
Author(s):  
Shouxin Cui ◽  
Wenxia Feng ◽  
Haiquan Hu ◽  
Zhenbao Feng ◽  
Yuanxu Wang
Keyword(s):  
Phase Transition ◽  
First Principles ◽  
First Principles Study ◽  
Zinc Blende ◽  
Rocksalt Phase

First-principles study of zinc-blende to rocksalt phase transition in BN

Open Physics ◽  
2010 ◽  
Vol 8 (4) ◽  
Author(s):  
Shouxin Cui ◽  
Wenxia Feng ◽  
Haiquan Hu ◽  
Zhenbao Feng
Keyword(s):  
Phase Transition ◽  
Cubic Boron Nitride ◽  
Structural Phase ◽  
Positive Pressure ◽  
Lattice Stability ◽  
Pressure Derivative ◽  
Zinc Blende ◽  
Rocksalt Phase ◽  
Valence Bands ◽  
Indirect Band Gap

AbstractThe structural, electronic and elastic properties of the cubic boron nitride (BN) compound are investigated by a first-principle pseudopotential method. The calculations show that the structural phase transition from the zinc-blende(ZB) structure to the rocksalt (RS) structure occurs at a transition pressure of 1088 GPa and with a volume reduction of 3.1%. Both the ZB and RS structures of BN have indirect gaps, with energy gaps of 4.80 eV and 2.11 eV, respectively. The positive pressure derivative of the indirect band gap (Γ-X) energy for the the ZB phase and the predicted ultrahigh metallization pressure are attributed to the absence of d occupations in the valence bands. The increase of the shear modulus with increasing pressure implies that the lattice stability becomes higher when BN is compressed.

Solvothermal Fabrication of Monodisperse Zinc-blende CdS Nanocrystals

2006 ◽  
Vol 35 (12) ◽  
pp. 1388-1389 ◽  
Author(s):  
Ming Chen ◽  
Lijia Pan ◽  
Jieming Cao ◽  
Mingbo Zheng ◽  
Yongping Chen ◽  
...  
Keyword(s):  
Cds Nanocrystals ◽  
Zinc Blende

scholarly journals Effect of Sintering Temperature on Metal-Insulator Phase Transition in La1-xCaxMnO3 Perovskites

2020 ◽  
Vol 2 (1) ◽  
pp. 37-42
Author(s):  
Arunachalam M ◽  
Thamilmaran P ◽  
Sakthipandi K
Keyword(s):  
Phase Transition ◽  
Bulk Modulus ◽  
Sintering Temperature ◽  
Magnetic Sensors ◽  
Temperature Dependent ◽  
Metal Insulator ◽  
Wide Range ◽  
Different Temperatures ◽  
Insulator Phase Transition

Lanthanum calcium based perovskites are found to be advantageous for the possible applications in magnetic sensors/reading heads, cathodes in solid oxide fuel cells, and frequency switching devices. In the present investigation La0.3Ca0.7MnO3 perovskites were synthesised through solid state reaction and sintered at four different temperatures such as 900, 1000, 1100 and 1200˚ C. X-ray powder diffraction pattern confirms that the prepared La0.3Ca0.7MnO3 perovskites have orthorhombic structure with Pnma space group. Ultrasonic in-situ measurements have been carried out on the La0.3Ca0.7MnO3 perovskites over wide range of temperature and elastic constants such as bulk modulus of the prepared La0.3Ca0.7MnO3 perovskites was obtained as function of temperature. The temperature-dependent bulk modulus has shown an interesting anomaly at the metal-insulator phase transition. The metal insulator transition temperature derived from temperature-dependent bulk modulus increases from temperature 352˚ C to 367˚ C with the increase of sintering temperature from 900 to 1200˚ C.

Soft bulk modulus at the configurational phase transition in Sm1−xYxS

1976 ◽  
Author(s):  
T. Penney ◽  
R. L. Melcher ◽  
F. Holtzberg ◽  
G. Güntherodt
Keyword(s):  
Phase Transition ◽  
Bulk Modulus

Isostructural phase transition-induced bulk modulus multiplication in dopant-stabilized ZrO2 solid solution

2019 ◽  
Vol 28 (7) ◽  
pp. 076109
Author(s):  
Min Wang ◽  
Wen-Shu Shen ◽  
Xiao-Dong Li ◽  
Yan-Chun Li ◽  
Guo-Zhao Zhang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid Solution ◽  
Bulk Modulus ◽  
Isostructural Phase Transition
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