The experimental results show that the coercivity of Nd-Fe-B sintermagnet decreases with increasing of the grain alignment degree of the magnets (i.e. decreasing of the orientation distribution coefficient σ).The coe...The experimental results show that the coercivity of Nd-Fe-B sintermagnet decreases with increasing of the grain alignment degree of the magnets (i.e. decreasing of the orientation distribution coefficient σ).The coercivities of the magnets with different orientation degree are calculated based on the pinning,nucleation and starting field theory,respectively.The comparison of the calculated values with the experimental results shows that the theoretical results are deviating from the experiments seriously for both pinning mechanism and nucleation mechanism. In contrast with that,the calculated values based on the starting field theory are in good agreement with the experimental results.展开更多
Introduction Nanofiber orientation in suspensions determines the performance of nanoparticle suspensions which have potential applications in intelligent control.Material and method Na2Ti3O7 nanofibers were prepared w...Introduction Nanofiber orientation in suspensions determines the performance of nanoparticle suspensions which have potential applications in intelligent control.Material and method Na2Ti3O7 nanofibers were prepared with a hydrothermal method.The orientation degree of Na2Ti3O7 nanofibers in silicone oil has been studied by in situ small-angle X-ray scattering technique.Thünemann–Ruland method was used to extract the distribution widths of Na2Ti3O7 nanofibers in the suspensions.Conclution An empirical formula has been proposed to describe the dependence of nanofiber orientation degree on the external electric-field strength(E)and the nanofiber concentration(C).The results demonstrate that the response of nanofiber orientation to the electric field can be divided into exponential and linear stages before and after the inflection point of electric-field strength(Ec0.09 kV/mm).Low concentration of suspension is more sensitive to the external electric field.The increase in nanofiber concentration will decrease the response sensitivity of nanofiber orientation degree to the change of E.The critical concentration of Na2Ti3O7 nanofibers in the suspension is about 5 wt%.This study is expected to give new clue for the structurally responsive mechanism of anisotropic nanoparticles in suspensions to electric-field strength and particle concentration.展开更多
文摘The experimental results show that the coercivity of Nd-Fe-B sintermagnet decreases with increasing of the grain alignment degree of the magnets (i.e. decreasing of the orientation distribution coefficient σ).The coercivities of the magnets with different orientation degree are calculated based on the pinning,nucleation and starting field theory,respectively.The comparison of the calculated values with the experimental results shows that the theoretical results are deviating from the experiments seriously for both pinning mechanism and nucleation mechanism. In contrast with that,the calculated values based on the starting field theory are in good agreement with the experimental results.
基金the Ministry of Science and Technology of China(Grant No.2017YFA0403000)the National Natural Science Foundation of China(Grant No.11405199).
文摘Introduction Nanofiber orientation in suspensions determines the performance of nanoparticle suspensions which have potential applications in intelligent control.Material and method Na2Ti3O7 nanofibers were prepared with a hydrothermal method.The orientation degree of Na2Ti3O7 nanofibers in silicone oil has been studied by in situ small-angle X-ray scattering technique.Thünemann–Ruland method was used to extract the distribution widths of Na2Ti3O7 nanofibers in the suspensions.Conclution An empirical formula has been proposed to describe the dependence of nanofiber orientation degree on the external electric-field strength(E)and the nanofiber concentration(C).The results demonstrate that the response of nanofiber orientation to the electric field can be divided into exponential and linear stages before and after the inflection point of electric-field strength(Ec0.09 kV/mm).Low concentration of suspension is more sensitive to the external electric field.The increase in nanofiber concentration will decrease the response sensitivity of nanofiber orientation degree to the change of E.The critical concentration of Na2Ti3O7 nanofibers in the suspension is about 5 wt%.This study is expected to give new clue for the structurally responsive mechanism of anisotropic nanoparticles in suspensions to electric-field strength and particle concentration.
