The effect of high magnetic fields on the morphology of Al-Mn phases was investigated. It is found that the tropism and the alignment of Al6Mn precipitated phases become regular under high magnetic fields. The stronge...The effect of high magnetic fields on the morphology of Al-Mn phases was investigated. It is found that the tropism and the alignment of Al6Mn precipitated phases become regular under high magnetic fields. The stronger the high magnetic fields, the more regular the alignment of Al6Mn precipitated phases. Al6Mn precipitated phases can generate oriented alignment and aggregation under high magnetic fields through the observation of the quenched microstructure of the Al-Mn alloy at different temperatures. Meanwhile, the number of Al6Mn phases increases continuously along with the increasing function time of high magnetic fields. X-ray diffraction also indicates that Al6Mn phases generate obvious tropism under high magnetic fields. The process of aggregation and growth of Al6Mn precipitated phases under the function of high magnetic fields after orientation were analyzed and discussed.展开更多
The influence of high magnetic field with different strength on the proeutectoid ferrite transformation in high purity Fe-0.36 wt% C during diffusional Υ phase transformation was studied. It was found that the format...The influence of high magnetic field with different strength on the proeutectoid ferrite transformation in high purity Fe-0.36 wt% C during diffusional Υ phase transformation was studied. It was found that the formation of acicular ferrite （ie. Widmanst3tten ferrite） was obviously suppressed by the applied high magnetic field. The stronger the magnetic field is, the more the ferrite grains elongating and aligning along the field direction will be. This is attributed to additional driving force for phase transformation and demagnetization effect introduced by the applied magnetic field. This is also considered to be related to the preferential growth of proeutectoid ferrite nuclei along field direction caused by magnetic dipolar interaction.展开更多
Nanocrystalline Mn0.6Zn0.4Fe2O4 particles are synthesized under magnetic fields of O and 6 T, and their structural and magnetic properties are investigated. The magnetic field enhances the grain size and the lattice s...Nanocrystalline Mn0.6Zn0.4Fe2O4 particles are synthesized under magnetic fields of O and 6 T, and their structural and magnetic properties are investigated. The magnetic field enhances the grain size and the lattice strain. Magnetic measurements show that the majority of the 6 T nanoparticles are superparamagnetic nearly from 40 to 300 K. It is interesting that the saturation magnetization of the 6 T sample is about 18% and 16% higher than that of the 0 T sample at 120 and 300K, respectively.展开更多
基金supported by the National Natural Science Foundation of China (No. 50674018)
文摘The effect of high magnetic fields on the morphology of Al-Mn phases was investigated. It is found that the tropism and the alignment of Al6Mn precipitated phases become regular under high magnetic fields. The stronger the high magnetic fields, the more regular the alignment of Al6Mn precipitated phases. Al6Mn precipitated phases can generate oriented alignment and aggregation under high magnetic fields through the observation of the quenched microstructure of the Al-Mn alloy at different temperatures. Meanwhile, the number of Al6Mn phases increases continuously along with the increasing function time of high magnetic fields. X-ray diffraction also indicates that Al6Mn phases generate obvious tropism under high magnetic fields. The process of aggregation and growth of Al6Mn precipitated phases under the function of high magnetic fields after orientation were analyzed and discussed.
基金supported by the National Natural Science Foundation of China (Grant Nos.50771026,50971034 and 50911130365)the Program for Changjiang Scholars and Innovative Research Team in University (Grant No.IRT0713)the Programme of Introducing Talents of Discipline to Universities (Grant No.B07015)
文摘The influence of high magnetic field with different strength on the proeutectoid ferrite transformation in high purity Fe-0.36 wt% C during diffusional Υ phase transformation was studied. It was found that the formation of acicular ferrite （ie. Widmanst3tten ferrite） was obviously suppressed by the applied high magnetic field. The stronger the magnetic field is, the more the ferrite grains elongating and aligning along the field direction will be. This is attributed to additional driving force for phase transformation and demagnetization effect introduced by the applied magnetic field. This is also considered to be related to the preferential growth of proeutectoid ferrite nuclei along field direction caused by magnetic dipolar interaction.
基金Supported by the Shanghai Rising-Star Program Grant No 07QA14026, the National Natural Science Foundation of China Grant Nos 10804072, 50703029 and 10774097, STCSM Grant Nos 08JC1410400, 0752nm012, and 0952nm02700, and FNEDAEDT under Grant No 200235.
文摘Nanocrystalline Mn0.6Zn0.4Fe2O4 particles are synthesized under magnetic fields of O and 6 T, and their structural and magnetic properties are investigated. The magnetic field enhances the grain size and the lattice strain. Magnetic measurements show that the majority of the 6 T nanoparticles are superparamagnetic nearly from 40 to 300 K. It is interesting that the saturation magnetization of the 6 T sample is about 18% and 16% higher than that of the 0 T sample at 120 and 300K, respectively.
