Three-dimensional flowerlike nanostructured metal oxides attached on the surfaces of Fe-based multi-phase nanocrys- talline ribbons （Fe-MNRs） were prepared by a simple way （through immersing the Fe-MNRs in Orange I...Three-dimensional flowerlike nanostructured metal oxides attached on the surfaces of Fe-based multi-phase nanocrys- talline ribbons （Fe-MNRs） were prepared by a simple way （through immersing the Fe-MNRs in Orange II solution）. It has been found that the as-prepared Fe-MNRs with 3D flowerlike nanostructures （Fe-MNRs ＋ FNs） exhibit good absorption property for a typical heavy metal ion （Cr^VI） in wastewater, while Fe-MNRs do not possess such properties. The Fe-MNRs ＋ FNs could remove 99% CrvI ions from the solution in 40 min, and this adsorption property can be attributed to the ion exchange between Cr^VI and surface hydroxyl groups （O-H） of 3D flowerlike nanostructures. The present result suggests that the Fe-MNRs ＋ FNs, prepared by facile way, possess great potentials in removing heavy metallic ions in wastewater.展开更多
The Fe78Si8B14 and Fe78P8B14 ribbons with different wheel speeds were prepared by melt-spinning, and their responses to He＋ ion irradiation were investigated. Previous studies had shown that the ion beam resistance c...The Fe78Si8B14 and Fe78P8B14 ribbons with different wheel speeds were prepared by melt-spinning, and their responses to He＋ ion irradiation were investigated. Previous studies had shown that the ion beam resistance capability of amorphous ribbons was better than their corresponding crystalline counterparts. However, no significant changes on the surface at low fluence are observed. At a relatively higher fluence, both the ribbons prepared at low and high wheel speeds behave the similar irradiation responses： peeling, flaking and multi-layer damages occur. The fully amorphous ribbons prepared at a high wheel speed can accommodate partial incident ions owing to the inherent disordered structure. As the irradiation fluence increases, they fail to accommodate the excess incident ions, which easily aggregate to result in the surface damage. While the partial amorphous ribbons prepared at a low wheel speed possess lots of unstable crystalline grain boundaries owing to the precipitation of Si-or P-rich phase, which may act as the source for the irradiation-induced defects annihilation. Results show that the size and the fraction of precipitate phases in amorphous matrix may play a dominated role in resisting the ion irradiation.展开更多
The effects of ribbon thickness(t)on the structure and magnetic properties of a Fe_(82.3)B_(13)Cu_(1.7)Nb_(3) alloy in melt-spun and annealed states have been investigated.Increasing the t from 15 to 23μm changes the...The effects of ribbon thickness(t)on the structure and magnetic properties of a Fe_(82.3)B_(13)Cu_(1.7)Nb_(3) alloy in melt-spun and annealed states have been investigated.Increasing the t from 15 to 23μm changes the structure of the melt-spun ribbons from a single amorphous phase to a composite with denseα-Fe nanograins embedded in the amorphous matrix.The grain size(D_(α-Fe))of theα-Fe near the free surface of the ribbon is about 6.7 nm,and it gradually decreases along the cross section toward the wheel-contacted surface.Further increasing the t to 32μm coarsens the D_(α-Fe) near the free surface to 15.2 nm and aggravates the D_(α-Fe) ramp along the cross section.After annealing,the ribbon with t=15μm has relatively largeα-Fe grains with D_(α-Fe)>30 nm,while the thicker ribbons possessing the pre-existing nanograins form a finer nanostructure with D_(α-Fe)<16 nm.The structural uniformity of the ribbon with t=23μm is better than that of the ribbon with t=32μm.The annealed ribbons with t=23 and 32μm possess superior soft magnetic properties to the ribbon with t=15μm.The ribbon with t=23μm exhibits a high saturation magnetic flux density of 1.68 T,low coercivity of 9.6 A/m,and high effective permeability at 1 kHz of 15,000.The ribbon with t=32μm has a slightly larger coercivity due to the lower structural uniformity.The formation mechanism of the fine nanostructure for the ribbons with suitable t has been discussed in terms of the competitive growth effect among the pre-existingα-Fe nanograins.展开更多
The structure, crystallization kinetics and magnetic property of as-quenched Fe_(73.5)Si_(13.5)B_9Nb_3Cu_1 amorphous ribbon(R0) as well as ribbons after autoclave treatment at 100°C and 150°C(R1 and R2) have...The structure, crystallization kinetics and magnetic property of as-quenched Fe_(73.5)Si_(13.5)B_9Nb_3Cu_1 amorphous ribbon(R0) as well as ribbons after autoclave treatment at 100°C and 150°C(R1 and R2) have been systematically studied by various techniques. With increasing autoclave treatment temperature,the measured structural, kinetic and magnetic parameters of samples increase firstly, i.e. R0 < R1; and then decrease or recover to the as-quenched sample, i.e. R2 < R1 or R2 ≈ R0. These results indicate that the SROs in R1 samples increased by transforming from fcc to bcc structure during the autoclave treatment and that the autoclave treatment can decrease the large radius(r_M) MRO(medium range order),but increase the small rMMRO. The measured structural, thermal and magnetic parameters of R2 sample have a tendency to recover toward as-quenched R0 sample. The thermal and magnetic parameters of samples after solely annealing treatment at higher temperature have no obvious recover phenomenon.The uneven actions of pressure and temperature in autoclave treatment may be helpful for us to search a new method to improve the magnetic properties of Fe-based glasses.展开更多
基金This work was supported by the National Key Basic Research and Development Programme （Grant No.2016YFB0300500） and the National Natural Science Foundation of China （NSFC, Grant Nos. 51571127 and 51771096）.
文摘Three-dimensional flowerlike nanostructured metal oxides attached on the surfaces of Fe-based multi-phase nanocrys- talline ribbons （Fe-MNRs） were prepared by a simple way （through immersing the Fe-MNRs in Orange II solution）. It has been found that the as-prepared Fe-MNRs with 3D flowerlike nanostructures （Fe-MNRs ＋ FNs） exhibit good absorption property for a typical heavy metal ion （Cr^VI） in wastewater, while Fe-MNRs do not possess such properties. The Fe-MNRs ＋ FNs could remove 99% CrvI ions from the solution in 40 min, and this adsorption property can be attributed to the ion exchange between Cr^VI and surface hydroxyl groups （O-H） of 3D flowerlike nanostructures. The present result suggests that the Fe-MNRs ＋ FNs, prepared by facile way, possess great potentials in removing heavy metallic ions in wastewater.
基金Acknowledgements The authors would like to acknowledge the support by the National Natural Science Foundation of China （Grant Nos. 51401028, 51271193, 11402277） and the Strategic Priority Research Program of the Chinese Academy of Sciences （Grant No. XDB22 040303）. The authors also thank to the support of Opening Fund of State Key Lab of Nuclear Physics and Technology at Peking University.
文摘The Fe78Si8B14 and Fe78P8B14 ribbons with different wheel speeds were prepared by melt-spinning, and their responses to He＋ ion irradiation were investigated. Previous studies had shown that the ion beam resistance capability of amorphous ribbons was better than their corresponding crystalline counterparts. However, no significant changes on the surface at low fluence are observed. At a relatively higher fluence, both the ribbons prepared at low and high wheel speeds behave the similar irradiation responses： peeling, flaking and multi-layer damages occur. The fully amorphous ribbons prepared at a high wheel speed can accommodate partial incident ions owing to the inherent disordered structure. As the irradiation fluence increases, they fail to accommodate the excess incident ions, which easily aggregate to result in the surface damage. While the partial amorphous ribbons prepared at a low wheel speed possess lots of unstable crystalline grain boundaries owing to the precipitation of Si-or P-rich phase, which may act as the source for the irradiation-induced defects annihilation. Results show that the size and the fraction of precipitate phases in amorphous matrix may play a dominated role in resisting the ion irradiation.
基金supported by the National Natural Science Foundation of China(Grant Nos.51871039,51771039 and 51571047)。
文摘The effects of ribbon thickness(t)on the structure and magnetic properties of a Fe_(82.3)B_(13)Cu_(1.7)Nb_(3) alloy in melt-spun and annealed states have been investigated.Increasing the t from 15 to 23μm changes the structure of the melt-spun ribbons from a single amorphous phase to a composite with denseα-Fe nanograins embedded in the amorphous matrix.The grain size(D_(α-Fe))of theα-Fe near the free surface of the ribbon is about 6.7 nm,and it gradually decreases along the cross section toward the wheel-contacted surface.Further increasing the t to 32μm coarsens the D_(α-Fe) near the free surface to 15.2 nm and aggravates the D_(α-Fe) ramp along the cross section.After annealing,the ribbon with t=15μm has relatively largeα-Fe grains with D_(α-Fe)>30 nm,while the thicker ribbons possessing the pre-existing nanograins form a finer nanostructure with D_(α-Fe)<16 nm.The structural uniformity of the ribbon with t=23μm is better than that of the ribbon with t=32μm.The annealed ribbons with t=23 and 32μm possess superior soft magnetic properties to the ribbon with t=15μm.The ribbon with t=23μm exhibits a high saturation magnetic flux density of 1.68 T,low coercivity of 9.6 A/m,and high effective permeability at 1 kHz of 15,000.The ribbon with t=32μm has a slightly larger coercivity due to the lower structural uniformity.The formation mechanism of the fine nanostructure for the ribbons with suitable t has been discussed in terms of the competitive growth effect among the pre-existingα-Fe nanograins.
基金financially supported by the National Key Research Program of China(No.2016YFB0300501)the Key Research Project of Shandong Province(No.2016GGX102010)the National Natural Science Foundation of China(Nos.51471099,51571132,51511140291 and 51771103)
文摘The structure, crystallization kinetics and magnetic property of as-quenched Fe_(73.5)Si_(13.5)B_9Nb_3Cu_1 amorphous ribbon(R0) as well as ribbons after autoclave treatment at 100°C and 150°C(R1 and R2) have been systematically studied by various techniques. With increasing autoclave treatment temperature,the measured structural, kinetic and magnetic parameters of samples increase firstly, i.e. R0 < R1; and then decrease or recover to the as-quenched sample, i.e. R2 < R1 or R2 ≈ R0. These results indicate that the SROs in R1 samples increased by transforming from fcc to bcc structure during the autoclave treatment and that the autoclave treatment can decrease the large radius(r_M) MRO(medium range order),but increase the small rMMRO. The measured structural, thermal and magnetic parameters of R2 sample have a tendency to recover toward as-quenched R0 sample. The thermal and magnetic parameters of samples after solely annealing treatment at higher temperature have no obvious recover phenomenon.The uneven actions of pressure and temperature in autoclave treatment may be helpful for us to search a new method to improve the magnetic properties of Fe-based glasses.
