Structure and magnetic properties of nitrides in FeNi and FeNiCo alloy particles synthesized via co-precipitation, reduction, and nitriding

Author(s):  
Mikio Kishimoto ◽  
Eiji Kita ◽  
Hideto Yanagihara
Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 341
Author(s):  
Tien Hiep Nguyen ◽  
Gopalu Karunakaran ◽  
Yu.V. Konyukhov ◽  
Nguyen Van Minh ◽  
D.Yu. Karpenkov ◽  
...  

This paper presents the synthesis of Fe–Co–Ni nanocomposites by chemical precipitation, followed by a reduction process. It was found that the influence of the chemical composition and reduction temperature greatly alters the phase formation, its structures, particle size distribution, and magnetic properties of Fe–Co–Ni nanocomposites. The initial hydroxides of Fe–Co–Ni combinations were prepared by the co-precipitation method from nitrate precursors and precipitated using alkali. The reduction process was carried out by hydrogen in the temperature range of 300–500 °C under isothermal conditions. The nanocomposites had metallic and intermetallic phases with different lattice parameter values due to the increase in Fe content. In this paper, we showed that the values of the magnetic parameters of nanocomposites can be controlled in the ranges of MS = 7.6–192.5 Am2/kg, Mr = 0.4–39.7 Am2/kg, Mr/Ms = 0.02–0.32, and HcM = 4.72–60.68 kA/m by regulating the composition and reduction temperature of the Fe–Co–Ni composites. Due to the reduction process, drastic variations in the magnetic features result from the intermetallic and metallic face formation. The variation in magnetic characteristics is guided by the reduction degree, particle size growth, and crystallinity enhancement. Moreover, the reduction of the surface spins fraction of the nanocomposites under their growth induced an increase in the saturation magnetization. This is the first report where the influence of Fe content on the Fe–Co–Ni ternary system phase content and magnetic properties was evaluated. The Fe–Co–Ni ternary nanocomposites obtained by co-precipitation, followed by the hydrogen reduction led to the formation of better magnetic materials for various magnetically coupled device applications.


2018 ◽  
Vol 44 (17) ◽  
pp. 20782-20789 ◽  
Author(s):  
Rohit R. Powar ◽  
Varsha D. Phadtare ◽  
Vinayak G. Parale ◽  
Hyung-Ho Park ◽  
Sachin Pathak ◽  
...  

2018 ◽  
Vol 56 (1) ◽  
pp. 31
Author(s):  
Luong Thi Quynh Anh ◽  
Nguyen Van Dan ◽  
Do Minh Nghiep

The crystalline nanoparticles of Ni0.2Zn0.8Fe2O4 ferrite were synthesized by chemical co-precipitation with precursor concentration of 0.1M, then modified by 0.25M solution of oleic acid in pentanol, finally heated at temperatures 120, 140, 160 and 180oC for 6h in autoclave. The XRD, EDS and TEM confirmed that all of samples are crystalline and their particle size are 6, 6.5, 7 and 8 nm. The magnetic properties showed that the coercive force, the remanence of samples are about zero, the saturation magnetization Ms has values from 14.20 to 27.12 emu/g.


2009 ◽  
Vol 23 (06n07) ◽  
pp. 1383-1388 ◽  
Author(s):  
MASLEEYATI YUSOP ◽  
DELIANG ZHANG ◽  
MARCUS WILSON ◽  
NICK STRICKLAND

Al 2 O 3-20 vol % Fe 70 Co 30 composite powders have been prepared by high energy ball milling a mixture of Al 2 O 3 powder and Fe 70 Co 30 alloy powder. The Fe 70 Co 30 alloy powder was also prepared by mechanical alloying of Fe and Co powders using the same process. The effects of milling duration from 8 to 48 hours on microstructure and magnetic properties of the nanostructured composite powders have been studied by means of X-ray Diffractometry (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). It was found that the nanostructured composite powder particles with irregular shapes and Fe 70 Co 30 alloy particles being embedded in them formed after 8 hours of milling. The average grain size of the Al 2 O 3 matrix reduced drastically to less than 18nm after 16 hours of milling. On the other hand, the embedded alloy particles demonstrated almost unchanged average grain size in the range of 14-15nm. Magnetic properties of the powder compacts at room temperature were measured from hysteresis curves, and show strong dependence of the milling time, with the coercivity increasing from 67.1 up to 127.9kOe with increasing the milling time from 8 to 48 hours. The possible microstructural reasons for this dependence are discussed.


2012 ◽  
Vol 736 ◽  
pp. 229-240 ◽  
Author(s):  
Sudhakar Panday ◽  
P. Jeevanandam ◽  
B.S. Sunder Daniel

This review article deals with the synthesis, characterization and magnetic properties of Co-Ni nanoalloys. The various physical and chemical methods for the synthesis of Co-Ni alloy nanoparticles are discussed. Co-Ni alloy nanoparticles with different size and shape such as spherical, rods, wires chain-like assembly are found to depend on the synthesis method and experimental condition. The structure of Co-Ni alloys is eitherfcc,hcpor mixedfccandhcpphase and found to depends on size, shape and concentration of Co in the Co-Ni alloys. Sodium hydroxide (NaOH) concentration and Co to Ni ratio influence the shape of bimetallic Co-Ni nanoparticles. Pt nucleating agents produced smaller size of Co-Ni alloy particles compared to Ru and Ag. Higher Co concentration in the Co-Ni alloys also influences the size alloy particles. The magnetic properties of Co-Ni nanoalloys depend on the size, shape and composition of the binary alloys. Surface oxidation of Co-Ni alloy nanoparticles decrease the saturation magnetization and increases with Co concentration in the alloys. The shape of Co-Ni alloy nanoparticles has an influence on coercivity. The microwave absorption properties of the Co-Ni alloys found to depend on the shape, size and composition of the binary alloys. The absorbance peaks shifts to higher frequency with decrease in size of the alloy particles. Potential applications of Co-Ni alloys in various fields are highlighted.


2010 ◽  
Vol 322 (21) ◽  
pp. 3470-3475 ◽  
Author(s):  
Yue Zhang ◽  
Zhi Yang ◽  
Di Yin ◽  
Yong Liu ◽  
ChunLong Fei ◽  
...  

2019 ◽  
Vol 546 (1) ◽  
pp. 48-56
Author(s):  
Ze Wu ◽  
Yang Song ◽  
Ruonan Zhang ◽  
Lianwei Shan ◽  
Limin Dong ◽  
...  

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