Single-band model of substitutional disordered ternary alloys in the coherent-potential approximation

1975 ◽  
Vol 11 (12) ◽  
pp. 4960-4979 ◽  
Author(s):  
Leonard M. Scarfone ◽  
James D. Chlipala
Keyword(s):  
Coherent Potential Approximation ◽  
Single Band ◽  
Ternary Alloys ◽  
Band Model ◽  
Potential Approximation

The Magnetic Properties of Disordered Transition Metal Alloys Using the Coherent Potential Approximation and Related Methods

1974 ◽  
Vol 52 (22) ◽  
pp. 2177-2209 ◽  
Author(s):  
M. J. Zuckermann
Keyword(s):  
Transition Metal ◽  
Magnetic Transition ◽  
Local Environment ◽  
Coherent Potential Approximation ◽  
Metal Alloys ◽  
Electronic Charge ◽  
Band Model ◽  
Magnetic Alloys ◽  
Potential Approximation ◽  
Transition Metal Alloys

For many years the properties of magnetic transition metal alloys were analyzed in terms of a rigid band model and the Stoner theory for magnetism in itinerant systems. Recently the introduction of the coherent potential approximation (CPA) has resulted in a description of the band structure of metallic alloys in terms of a local electronic charge density of states. The CPA and related approximations are derived in detail in this article and it is shown how these approximations have been extended to describe the properties of magnetic transition metal alloys in terms of local electronic spin densities. Both the statics and dynamics of itinerant magnetic alloys are discussed and the comparison with experiment is examined in detail. The article is concluded with a description of possible improvements to the CPA for magnetic alloys in particular for local environment effects.

A model for the bandgap energy of the dilute nitride InGaNAs alloys by modifying simplified coherent potential approximation

2014 ◽  
Vol 28 (08) ◽  
pp. 1450066 ◽  
Author(s):  
Chuan-Zhen Zhao ◽  
You-Yang Qu ◽  
Tong Wei ◽  
Xiao-Dong Sun ◽  
Sha-Sha Wang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Composition Range ◽  
Coherent Potential Approximation ◽  
Ternary Alloys ◽  
Bandgap Energy ◽  
Dilute Nitride ◽  
Potential Approximation ◽  
Physical Mechanisms

In this paper, a model describing the bandgap energy of the dilute nitride alloy In x Ga 1-x N y As 1-y is developed based on the modification of simplified coherent potential approximation (MSCPA) and the band anti-crossing model (BAC). The parameters in the model are obtained by fitting the experimental bandgap energies of the ternary alloys InGaAs , InGaN , GaNAs and InNAs . It is found that the results agree well with the experimental data. We also find that although the bandgap energies of In x Ga 1-x N y As 1-y and In x Ga 1-x As can be calculated by using MSCPA, the physical mechanisms for the bandgap evolution of In x Ga 1-x N y As 1-y and In x Ga 1-x As are very different. In addition, it is found that the model in this work may be used in a larger composition range than the BAC model.

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