Study of the thermal and temperature conditions of flat and inclined lands tekis va qiyalik yerlarning issiqlik va temperatura rejimini o

* GULISTON DAVLAT UNIVERSITETI AXBOROTNOMASI,
Tabiiy va qishloq xo‘jaligi fanlari seriyasi. 2021. № 1
11 
Fig. 4. Dissolution of gallium arsenide in the form of GaAs molecules (a), as well as gallium 
and arsenic in the form of separate Ga and As atoms (b) in tin at the temperature of 750

С. 
Fig. 5. Dissolution of zinc selenide in the form of ZnSe molecules (a), as well as zinc and 
selenium in the form of separate Zn and Se atoms (b) in tin at the temperature of 750

C. 
In addition, one of the main conditions for liquid-phase epitaxy is that the solution-melt must be 
supersaturated with the components of the solid solution, i.e. both GaAs and ZnSe. If GaAs and ZnSe 
molecules in Sn decompose into individual Ga, As, Zn and Se atoms, then with the content of 4.6 
mol.% GaAs and 0.3 mol.% ZnSe in Sn at 720°C, the solution-melt, according to the state diagram of 
the alloys, will not be supersaturated not with gallium, not arsenic, not zinc and not selenium, and 
epitaxial growth of the (GaAs)
1-x
(ZnSe)
x
solid solution should not occur. The fact that epitaxial 
growth of (GaAs)
1-x
(ZnSe)
x
is observed under these conditions indicates that the tin solution-melt is 
supersaturated with both GaAs and ZnSe molecules, and that GaAs and ZnSe molecules do not 
disintegrate into individual atoms Ga, As, Zn and Se. 
Therefore, we assume that GaAs and ZnSe in liquid tin are mainly in the form of GaAs and 
ZnSe molecules (Fig. 1). Since the sum of the covalent radii of the atoms of GaAs (r
Ga
+ r
As
= 2.43 Å) 
and ZnSe (r
Zn
+ r
Se
= 2.45 Å) molecules are close, and the sum of the valences of their atoms are equal 
(z
Ga
+ z
As
= z
Zn
+ z
Se
), then, consequently, the substitution of diatomic molecules in lattice sites of a 
solid solution are energetically more favorable (Fig. 6) than atomic substitution of a crystal lattice site 
by Ga, As, Zn or Se atoms separately. 
In fig. 6 shows the tetrahedral lattice of the GaAs binary compound. Atom Ga* (cationic lattice 
site) and As* (anionic lattice site) are in the center of the corresponding tetrahedra. The Ga* atom has 
3 valence electrons, and all of them will participate in the formation of covalent bonds with three 
neighboring As atoms - bonds (1), (2) and (3) (see Fig. 6). The As* atom has 5 valence electrons, 3 of 

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