Superconductive properties for oxides were predicted by artificial neural network (ANN) method with structural and chemical parameters as inputs. The predicted properties include superconductivity for oxides, distribu...Superconductive properties for oxides were predicted by artificial neural network (ANN) method with structural and chemical parameters as inputs. The predicted properties include superconductivity for oxides, distributed ranges of the superconductive transition temperature (Tc) for complex oxides, and Tc values for cuprate superconductors. The calculated results indicated that the adjusted ANN can be used to predict superconductive properties for unknown oxides.展开更多
In this paper,we report the measurements of the specific heat of the lanthanide oxides(La_2O_3,CeO_2, Pr_6O_(11),Nd_2O_3,Sm_2O_3,Eu_2O_3,Gd_2O_3,Tb_4O_7,Dy_2O_3,Ho_2O_3,Er_2O_3,Tm_2O_3,Yb_2O_3,Lu_2O_3)from-150℃ to 80...In this paper,we report the measurements of the specific heat of the lanthanide oxides(La_2O_3,CeO_2, Pr_6O_(11),Nd_2O_3,Sm_2O_3,Eu_2O_3,Gd_2O_3,Tb_4O_7,Dy_2O_3,Ho_2O_3,Er_2O_3,Tm_2O_3,Yb_2O_3,Lu_2O_3)from-150℃ to 800℃ by using adiabatic scanning calorimeter.We found that chemical reactions occur during the heating pro- cess of initial La_2O_3 and Nd_2O_3 materials by using DTA and X-ray diffraction.The results of specific heat measurement show that except CeO_2 and Tb_4O_7,other twelve lanthanide oxides were accompanied with endothermal change and weight loss to a certain degree during the heating process.展开更多
The relations of oxygen content, critical temperature TC and mean ionization potential < U0> of superconducting oxides are reported. We found that in oxides oxygen is the major element which governs their < U...The relations of oxygen content, critical temperature TC and mean ionization potential < U0> of superconducting oxides are reported. We found that in oxides oxygen is the major element which governs their < U0> te values and thus oxygen content plays an jmportant role in their superconducting properties. As for Y(123)- and T1-systems oxygenation may improve their TC values, but for Biand Hg-systems oxygenation process is not so important. In Y(123), as the oxygen content increase results in the increase of TC upon < U0>to, while the substitution of Ba2+ by Sr2+ causes the decrease of TC upon < U0 >. These results may provide some clues about the superconductivity of oxides and support further that < Uo > is really a good criterion for oxide superconductivity. Two kinds of possible superconducting oxides are predicted in this paper according to the mean ionization potential criterion.展开更多
The properties of superconductivity of some oxides were investigated by structural parametric diagrams or pattern recognition with structural chemical parameters. The essential criteria of superconductivity for some o...The properties of superconductivity of some oxides were investigated by structural parametric diagrams or pattern recognition with structural chemical parameters. The essential criteria of superconductivity for some oxides have been obtained by using 109 oxides as the training set and seven parameters as features; the results illustrated that the electronegativity difference is the most important factor among seven parameters. Moreover, the regularity of superconductive transition temperature Tc for complex oxides is discussed by partial least squares (PLS) method.展开更多
By means of X-ray diffraction and adiabatic scanning calorimeter,the specific heats of five compounds in the Sm_2O_3-BaO--CuO system,such as Sm_2BaO_4,Sm_2CuO_4,BaCuO_4, Sm_2BaCuO_5,SmBa_2Cu_3O_(7-x),from -150℃ to 80...By means of X-ray diffraction and adiabatic scanning calorimeter,the specific heats of five compounds in the Sm_2O_3-BaO--CuO system,such as Sm_2BaO_4,Sm_2CuO_4,BaCuO_4, Sm_2BaCuO_5,SmBa_2Cu_3O_(7-x),from -150℃ to 800℃ have been measured.It is found that the specific heats of these compounds increase smoothly with the increase of temperature.展开更多
文摘Superconductive properties for oxides were predicted by artificial neural network (ANN) method with structural and chemical parameters as inputs. The predicted properties include superconductivity for oxides, distributed ranges of the superconductive transition temperature (Tc) for complex oxides, and Tc values for cuprate superconductors. The calculated results indicated that the adjusted ANN can be used to predict superconductive properties for unknown oxides.
文摘In this paper,we report the measurements of the specific heat of the lanthanide oxides(La_2O_3,CeO_2, Pr_6O_(11),Nd_2O_3,Sm_2O_3,Eu_2O_3,Gd_2O_3,Tb_4O_7,Dy_2O_3,Ho_2O_3,Er_2O_3,Tm_2O_3,Yb_2O_3,Lu_2O_3)from-150℃ to 800℃ by using adiabatic scanning calorimeter.We found that chemical reactions occur during the heating pro- cess of initial La_2O_3 and Nd_2O_3 materials by using DTA and X-ray diffraction.The results of specific heat measurement show that except CeO_2 and Tb_4O_7,other twelve lanthanide oxides were accompanied with endothermal change and weight loss to a certain degree during the heating process.
文摘The relations of oxygen content, critical temperature TC and mean ionization potential < U0> of superconducting oxides are reported. We found that in oxides oxygen is the major element which governs their < U0> te values and thus oxygen content plays an jmportant role in their superconducting properties. As for Y(123)- and T1-systems oxygenation may improve their TC values, but for Biand Hg-systems oxygenation process is not so important. In Y(123), as the oxygen content increase results in the increase of TC upon < U0>to, while the substitution of Ba2+ by Sr2+ causes the decrease of TC upon < U0 >. These results may provide some clues about the superconductivity of oxides and support further that < Uo > is really a good criterion for oxide superconductivity. Two kinds of possible superconducting oxides are predicted in this paper according to the mean ionization potential criterion.
文摘The properties of superconductivity of some oxides were investigated by structural parametric diagrams or pattern recognition with structural chemical parameters. The essential criteria of superconductivity for some oxides have been obtained by using 109 oxides as the training set and seven parameters as features; the results illustrated that the electronegativity difference is the most important factor among seven parameters. Moreover, the regularity of superconductive transition temperature Tc for complex oxides is discussed by partial least squares (PLS) method.
基金The project supported by the National Natural Science Foundation of China
文摘By means of X-ray diffraction and adiabatic scanning calorimeter,the specific heats of five compounds in the Sm_2O_3-BaO--CuO system,such as Sm_2BaO_4,Sm_2CuO_4,BaCuO_4, Sm_2BaCuO_5,SmBa_2Cu_3O_(7-x),from -150℃ to 800℃ have been measured.It is found that the specific heats of these compounds increase smoothly with the increase of temperature.
