Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li +,K +//CO 2- 3,B 4O 2- 7-H 2O at 288 K were experimentally studied with the isothermal equilibrium method. The ...Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li +,K +//CO 2- 3,B 4O 2- 7-H 2O at 288 K were experimentally studied with the isothermal equilibrium method. The phase diagram of the system consisted of two invariant points E and F, five univariant curves, and four crystallization fields that belonged to K 2CO 3·3/2H 2O,Li 2 B 4O 7·3H 2O, K 2 B 4O 7 ·4H 2O and Li 2CO 3. The composition of the solution corresponding to E was w(CO 2- 3)=2.27 %, w(B 4O 2- 7) =6.05 %, w(K + ) =4.30%,w(Li + )=0.30 % and the equilibrium solids were Li 2 B 4O 7· 3H 2O+K 2 B 4O 7·4H 2O+Li 2CO 3;The composition of the solution for F was w(CO 2- 3) =22.45%,w(B 4O 2- 7)=1.88%,w(K + )=29.96%,w(Li + )=0.03% and the equilibrium solids were K 2CO 3·3/2H 2O+ K 2 B 4O 7·4H 2O+Li 2CO 3. K 2CO 3 possesses strong salting-out effect on K 2 B 4O 7,Li 2CO 3 and Li 2 B 4O 7.展开更多
YBa2Cu3O7-x （YBCO） superconducting film was fabricated on {001} LaAlO3 （LAO） substrate by pulse laser deposition （PLD）, and its microstructure was examined by high resolution X-ray diffraction technology （HRXRD...YBa2Cu3O7-x （YBCO） superconducting film was fabricated on {001} LaAlO3 （LAO） substrate by pulse laser deposition （PLD）, and its microstructure was examined by high resolution X-ray diffraction technology （HRXRD）, such as pole figure, rocking curve, reciprocal space mapping. The results show that the YBCO crystalline alignment is almost {001}YBCO//{001}LAO, 100YBCO//100LAO besides 2% {001}YBCO//{001}LAO, 110YBCO//100LAO. The out-plane alignment of YBCO is some spreading （the breadth is 0.75°）. There are 90°±0.65°110 twin domains in the film, which is caused by the high local stress and stress difference between 100 and 010 during the tetragonal to orthorhombic phase transition.展开更多
The adsorption and the growth of ZnO on α-Al2O3（0001） surface at various temperatures were theoretically calculated by using a plane wave pseudopotentials （USP） method based on density functional theory.The avera...The adsorption and the growth of ZnO on α-Al2O3（0001） surface at various temperatures were theoretically calculated by using a plane wave pseudopotentials （USP） method based on density functional theory.The average adsorption energy of ZnO at 400, 600 and 800 ℃ is 4.16±0.08, 4.25±0.11 and 4.05±0.23 eV respectively. Temperature has a remarkable effect on the structure of the surface and the interface of ZnO/α-Al2O3（0001）. It is found that the Zn-hexagonal symmetry deflexion does not appear during the adsorption growth of ZnO at 400 ℃, and that the ZnO[10^-10] is parallel with the [10^-10] of the α-Al2O3（0001）, which is favorable for forming ZnO film with the Zn-terminated surface. It is observed from simulation that there are two kinds of surface structures in the adsorption of ZnO at 600 ℃： one is the ZnO surface that has the Zn-terminated structure, and whose [10^-10] parallels the [10^-10] of the substrate surface, and the other is the ZnO[10^-10] //sapphire [11-20] with the O-terminated surface. The energy barrier of the phase transition between these two different surface structures is about 1.6 eV, and the latter is more stable. Therefore,the suitable temperature for the thin film growth of ZnO on sapphire is about 600 ℃, and it facilitates the formation of wurtzite structure containing Zn-O-Zn-O-Zn-O double-layers as a growth unit-cell. At 600 ℃, the average bond length of Zn-O is 0.190±0.01 nm, and the ELF value indicates that the bond of （substrate）-O-Zn-O has a distinct covalent character, whereas the （Zn）O-Al （substrate） shows a clear character of ionic bond. However, at a temperature of 800 ℃, the dissociation of Al and O atoms on the surface of the α-Al2O3（0001） leads to a disordered surface and interface structure. Thus, the Zn-hexagonal symmetry structure of the ZnO film is not observed under this condition.展开更多
文摘Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li +,K +//CO 2- 3,B 4O 2- 7-H 2O at 288 K were experimentally studied with the isothermal equilibrium method. The phase diagram of the system consisted of two invariant points E and F, five univariant curves, and four crystallization fields that belonged to K 2CO 3·3/2H 2O,Li 2 B 4O 7·3H 2O, K 2 B 4O 7 ·4H 2O and Li 2CO 3. The composition of the solution corresponding to E was w(CO 2- 3)=2.27 %, w(B 4O 2- 7) =6.05 %, w(K + ) =4.30%,w(Li + )=0.30 % and the equilibrium solids were Li 2 B 4O 7· 3H 2O+K 2 B 4O 7·4H 2O+Li 2CO 3;The composition of the solution for F was w(CO 2- 3) =22.45%,w(B 4O 2- 7)=1.88%,w(K + )=29.96%,w(Li + )=0.03% and the equilibrium solids were K 2CO 3·3/2H 2O+ K 2 B 4O 7·4H 2O+Li 2CO 3. K 2CO 3 possesses strong salting-out effect on K 2 B 4O 7,Li 2CO 3 and Li 2 B 4O 7.
基金Project (50972019) supported by the National Natural Science Foundation of ChinaProject (2011CBA00105) supported by the National Basic Research Program of China
文摘YBa2Cu3O7-x （YBCO） superconducting film was fabricated on {001} LaAlO3 （LAO） substrate by pulse laser deposition （PLD）, and its microstructure was examined by high resolution X-ray diffraction technology （HRXRD）, such as pole figure, rocking curve, reciprocal space mapping. The results show that the YBCO crystalline alignment is almost {001}YBCO//{001}LAO, 100YBCO//100LAO besides 2% {001}YBCO//{001}LAO, 110YBCO//100LAO. The out-plane alignment of YBCO is some spreading （the breadth is 0.75°）. There are 90°±0.65°110 twin domains in the film, which is caused by the high local stress and stress difference between 100 and 010 during the tetragonal to orthorhombic phase transition.
文摘The adsorption and the growth of ZnO on α-Al2O3（0001） surface at various temperatures were theoretically calculated by using a plane wave pseudopotentials （USP） method based on density functional theory.The average adsorption energy of ZnO at 400, 600 and 800 ℃ is 4.16±0.08, 4.25±0.11 and 4.05±0.23 eV respectively. Temperature has a remarkable effect on the structure of the surface and the interface of ZnO/α-Al2O3（0001）. It is found that the Zn-hexagonal symmetry deflexion does not appear during the adsorption growth of ZnO at 400 ℃, and that the ZnO[10^-10] is parallel with the [10^-10] of the α-Al2O3（0001）, which is favorable for forming ZnO film with the Zn-terminated surface. It is observed from simulation that there are two kinds of surface structures in the adsorption of ZnO at 600 ℃： one is the ZnO surface that has the Zn-terminated structure, and whose [10^-10] parallels the [10^-10] of the substrate surface, and the other is the ZnO[10^-10] //sapphire [11-20] with the O-terminated surface. The energy barrier of the phase transition between these two different surface structures is about 1.6 eV, and the latter is more stable. Therefore,the suitable temperature for the thin film growth of ZnO on sapphire is about 600 ℃, and it facilitates the formation of wurtzite structure containing Zn-O-Zn-O-Zn-O double-layers as a growth unit-cell. At 600 ℃, the average bond length of Zn-O is 0.190±0.01 nm, and the ELF value indicates that the bond of （substrate）-O-Zn-O has a distinct covalent character, whereas the （Zn）O-Al （substrate） shows a clear character of ionic bond. However, at a temperature of 800 ℃, the dissociation of Al and O atoms on the surface of the α-Al2O3（0001） leads to a disordered surface and interface structure. Thus, the Zn-hexagonal symmetry structure of the ZnO film is not observed under this condition.
