The effect of Gd content on microstructure and magnetic properties of sintered Nd33.03-xGdxFe65.65B1.32 （x=0-2） was studied in this paper to improve the thermal stability of NdFeB and to reduce the raw material cost...The effect of Gd content on microstructure and magnetic properties of sintered Nd33.03-xGdxFe65.65B1.32 （x=0-2） was studied in this paper to improve the thermal stability of NdFeB and to reduce the raw material cost. The results showed that better magnet performance could be obtained by adding Gd （0-1.5 wt.%） with partial substitution of Nd in Nd33.03-xGdxFe65.65B1.32. It was also found that the Nd33.03-xGdxFe65.65B1.32 magnets showed the best performance when Gd addition increased to 1.0 wt.%. The temperature coefficient Br （α） could be improved from -0.15%/oC to -0.063%/oC （maximum work temperature 120 oC） and the Curie temperature could be improved from 315 oC to 323 oC because the Gd2Fe14B had positive temperature coefficient Br （α） and higher Curie temperature than that of Nd2Fe14B. The coercivity could be improved from 10.2 to 11.48 kOe and the microstructure was close to ideal microstructure. The magnetic performance decreased sharply by adding Gd （above 2 wt.%） with partial substitution of Nd in Nd33.03-xGdxFe65.65B1.32 because the Gd element concen-trated in the grain boundaries.展开更多
The effects of Gd content on crystalline orientation, microstructure and superconductivity of GdxYl-x-BazCu3O7-δ（GdYBCO） films were systematically investigated. By varying the Gd content in the liquid precursor wit...The effects of Gd content on crystalline orientation, microstructure and superconductivity of GdxYl-x-BazCu3O7-δ（GdYBCO） films were systematically investigated. By varying the Gd content in the liquid precursor without changing the total amount of rare earth elements, series of GdYBCO films with x values of 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0 were fabricated by metal organic chemical vapor deposition （MOCVD）. X-ray diffraction （XRD） and scanning electron microscope （SEM） analysis revealed that Gd introducing could restrain the formation of CuYOa phase, but induce a-axis growth of GdYBCO film. The increase of x from 0 to 0.5 leads to enhancing critical current density at self-field and 77 K （Jcs0 from 1.8 to 2.8 MA.cm^-2, which benefits from the decrease in CuYO2 impurities and improvement of in-plane texture from 5.0° to 4.3°. However, raising x from 0.5 to 1.0 gives rise to abundant a-axis growth of film and degradation of in-plane texture from 4.3° to 5.4°, consequently resulting in the decrease OfJcsf from 2.8 to 0.8 MA.cm^-2. Even though Jcsf has not varied monotonically, the critical transition temperature of GdYBCO films linearly increases from 90.75 to 92.25 K and the in-field performance at magnetic field （B） of 0-1.1 T and 77 K as well as B parallel to film normal is also superior with Gd content increasing.展开更多
基金Project supported by Application of Rare Earth Project of Ministry of Industry and Information Technology of the People's Republic of China (2010 No.1)
文摘The effect of Gd content on microstructure and magnetic properties of sintered Nd33.03-xGdxFe65.65B1.32 （x=0-2） was studied in this paper to improve the thermal stability of NdFeB and to reduce the raw material cost. The results showed that better magnet performance could be obtained by adding Gd （0-1.5 wt.%） with partial substitution of Nd in Nd33.03-xGdxFe65.65B1.32. It was also found that the Nd33.03-xGdxFe65.65B1.32 magnets showed the best performance when Gd addition increased to 1.0 wt.%. The temperature coefficient Br （α） could be improved from -0.15%/oC to -0.063%/oC （maximum work temperature 120 oC） and the Curie temperature could be improved from 315 oC to 323 oC because the Gd2Fe14B had positive temperature coefficient Br （α） and higher Curie temperature than that of Nd2Fe14B. The coercivity could be improved from 10.2 to 11.48 kOe and the microstructure was close to ideal microstructure. The magnetic performance decreased sharply by adding Gd （above 2 wt.%） with partial substitution of Nd in Nd33.03-xGdxFe65.65B1.32 because the Gd element concen-trated in the grain boundaries.
基金financially supported by the National Science Foundation of China (No.91421110)the National High Technology Research and Development Program of China (No.2014AA032702)+2 种基金the National Basic Research Program of China (No.2015CB358600)the Sichuan Youth Science and Technology Innovation Research Team Funding (No.2011JTD0006)the Sichuan Provincial Fund for Distinguished Young Academic and Technology Leaders (No.2014JQ0011)
文摘The effects of Gd content on crystalline orientation, microstructure and superconductivity of GdxYl-x-BazCu3O7-δ（GdYBCO） films were systematically investigated. By varying the Gd content in the liquid precursor without changing the total amount of rare earth elements, series of GdYBCO films with x values of 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0 were fabricated by metal organic chemical vapor deposition （MOCVD）. X-ray diffraction （XRD） and scanning electron microscope （SEM） analysis revealed that Gd introducing could restrain the formation of CuYOa phase, but induce a-axis growth of GdYBCO film. The increase of x from 0 to 0.5 leads to enhancing critical current density at self-field and 77 K （Jcs0 from 1.8 to 2.8 MA.cm^-2, which benefits from the decrease in CuYO2 impurities and improvement of in-plane texture from 5.0° to 4.3°. However, raising x from 0.5 to 1.0 gives rise to abundant a-axis growth of film and degradation of in-plane texture from 4.3° to 5.4°, consequently resulting in the decrease OfJcsf from 2.8 to 0.8 MA.cm^-2. Even though Jcsf has not varied monotonically, the critical transition temperature of GdYBCO films linearly increases from 90.75 to 92.25 K and the in-field performance at magnetic field （B） of 0-1.1 T and 77 K as well as B parallel to film normal is also superior with Gd content increasing.
