Dissertation > Mathematical sciences and chemical > Physics > Solid State Physics > Solid nature of the > Magnetic properties

Structure and Magnetic Properties of Nanocrystalline Fe-Co-Nb(V)Si-B-Cu Soft Magnetic Alloys

Author WangGuangJian
Tutor WangZhi
School Tianjin University
Course Condensed Matter Physics
Keywords Annealing temperature Nanocrystalline Alloys Lattice constant Crystallized volume Initial permeability Curie temperature Cut - off frequency of use
CLC O482.5
Type Master's thesis
Year 2006
Downloads 204
Quotes 1
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Co containing FINEMET type (Fe 0.5 Co 0.5 ) 73.5 Nb 3 Si , 13.5 < / sub> B 9 Cu 1 and (Fe0.5Co0.5) 73.5Nb2V1Si13.5B9Cu1 alloy after different temperature nanocrystallization of structure and soft magnetic properties. The results show that with the free of the Co of FINEMET type Fe 73.5 Nb 3 Si 13.5 B 9 Cu , 1 and Fe 73.5 Nb 2 V 1 Si 13.5 B 9 Cu 1 alloy, two alloys available at a lower temperature to achieve nanocrystallization, good soft magnetic properties can be obtained after the 460 ° C nanocrystallization. With the annealing temperature, the nanocrystals gradually grew up, the soft magnetic properties of the alloy began to decline; hard magnetic phase of Fe-B begins to precipitate when the annealing temperature is higher than the secondary crystallization temperature above 600 ℃ (FeCo) -B, rapid decline in the soft magnetic properties of the alloy. Alternative FINEMET type alloy of Fe with Co part of the two nanocrystalline alloys quenched Curie temperature TC am significantly improved, up to 460 ° C. After the high temperature properties of the 460 ℃ nanocrystalline after two alloys, (Fe 0.5 Co 0.5 ) 73.5 Nb 3 Si 13.5 B 9 Cu 1 the nanocrystalline alloys initial permeability at 300 ℃ or less remained constant while the formed V partial substitution of Nb (Fe 0.5 Co. 0.5 ) 73.5 Nb 2 V 1 Si 13.5 B 9 nanocrystalline alloy Cu 1 reduced the proportion of Co in the allocation of the residual amorphous, and further improve the permeability However, its initial permeability can only be kept constant, when the temperature is higher than 200 ° C within 200 ℃ significantly attenuated and its permeability lower than after the temperature reached 320 ° C (Fe 0.5 Co 0.5 ) 73.5 Nb 3 Si 13.5 B 9 Cu 1 < / sub> nanocrystalline alloys. An appropriate increase in the annealing temperature, a fraction of the capacity volume of the crystalline phase of the alloy, although the decrease of the initial permeability at room temperature, but will delay the attenuation of the initial magnetic permeability at a high temperature. 580 ° C annealed alloys (Fe , 0.5 Co 0.5 ) 73.5 the Nb 2 V 1 Si 13.5 B 9 Cu 1 of the initial magnetic permeability μi at 600 ℃ attenuation small, having a good temperature stability and structural stability. The experimental results on seeking new type of high-temperature nanocrystalline soft magnetic alloy has a certain significance. Alloys studied using an impedance analyzer (Fe 0.5 Co 0.5 ) 73.5 Nb 2 V 1 < / sub> Si 13.5 B 9 Cu 1 initial magnetic permeability and the cut-off frequency of use vary with the annealing temperature. The results show that the FeCo nanocrystalline alloy determine the initial permeability and the cut-off frequency of use factors of domain wall pinning elastic recovery coefficient α, with the lowering of the annealing temperature initial permeability, the cut-off frequency fo increases, the initial permeability μi and cutoff frequency fo both product μi fo basically unchanged in a very wide range of annealing temperatures.

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