In order to prepare the bulk samples with high residual magnetization of magnetic compounds, such as (Sm, La)2(Co,Cu,Fe,Zr)17, (Sm,La)1(Co,Cu, Fe)5, Nd2Fe14B, and Pr2Fe14B, directly prepared by solidification, or hot-...In order to prepare the bulk samples with high residual magnetization of magnetic compounds, such as (Sm, La)2(Co,Cu,Fe,Zr)17, (Sm,La)1(Co,Cu, Fe)5, Nd2Fe14B, and Pr2Fe14B, directly prepared by solidification, or hot-deformation , it is the first thing to explore the possibilities of the easy magnetization axis of the whole bulk samples to be arranged in one designed direction. a is defined as the angle between the axis and the direction. In Sm-La-Co-Fe-Cu-Zr system, whetherαis equal to 0°or 90°depends upon not only alloy compositions but also the ratio of the temperature gradient at the solid/liquid interface and the crystal growth rate. To some alloys, a can be changed from 90°to 0°if the ratio is increased to be higher than a critical value, so the c-axis texture orientation can be obtained. In Nd-Fe-B system, the easy magnetization axis of Nd2Fe14B is always perpendicular to the preferential growth direction [ 100], and the easy magnetization axes of Nd2Fe14B grains are randomly distributed in the plane normal to the growth direction even if the growth rate is decreased from 250 to 12μm·-1. But if the magnetization axis of the anisotropic magnet substrate is perpendicular to the heat flux direction of the laser melting solidification layer, c-axis texture of the columnar Nd2Fe14B grains in the layer can be obtained, which is the same as that of the substrate, if the laser scanning rate is not less than 25μm·s-2. Also the c-axis texture [006] can be achieved through hot-deformation of PrxFe93.5-xB5Cu1.5(x = 15 - 19) under the conditions of hot-pressing temperature 973 ~ 1273 K, strain rate 10-3 S-1, and strain 50% ~ 80% .展开更多
Using in situ electric-field-modulated anisotropic magnetoresistance measurement, a large reversible and non- volatile in-plane rotation of magnetic easy axis of -35° between the positive and negative electrical ...Using in situ electric-field-modulated anisotropic magnetoresistance measurement, a large reversible and non- volatile in-plane rotation of magnetic easy axis of -35° between the positive and negative electrical poling states is demonstrated in C040Fe40B20//（001）-cut Pb（Mgl/3Nb2/3）O3-25PbTiO3 （PMN-PT）. The specific magneto- electric coupling mechanism therein is experimentally verified to be related to the synchronous in-plane strain rotation induced by 109° ferroelastic domain switching in the （001）-cut PMN-PT substrate.展开更多
Slanted Fe nanorods prepared by glancing angle deposition on silicon substrates exhibited easy magnetization along their growth axis. By using a thin gold film on a silicon substrate as a buffer layer, slanted Fe nano...Slanted Fe nanorods prepared by glancing angle deposition on silicon substrates exhibited easy magnetization along their growth axis. By using a thin gold film on a silicon substrate as a buffer layer, slanted Fe nanorods can be realigned towards the substrate surface normal by a strong magnetic field. After realignment, the Fe nanorods retained the easy magnetization axis along their growth axis. The effects of the realignment by the strong magnetic field on the properties of the slanted Fe nanorods were also investigated. This study provides a possible way to fabricate magnetic nanostructures for perpendicular recording applications.展开更多
基金Project supported by Ministry of Science and Technology (2004CCA04000)Zhejiang Provincial Natural Science Fund of China (M503096)
文摘In order to prepare the bulk samples with high residual magnetization of magnetic compounds, such as (Sm, La)2(Co,Cu,Fe,Zr)17, (Sm,La)1(Co,Cu, Fe)5, Nd2Fe14B, and Pr2Fe14B, directly prepared by solidification, or hot-deformation , it is the first thing to explore the possibilities of the easy magnetization axis of the whole bulk samples to be arranged in one designed direction. a is defined as the angle between the axis and the direction. In Sm-La-Co-Fe-Cu-Zr system, whetherαis equal to 0°or 90°depends upon not only alloy compositions but also the ratio of the temperature gradient at the solid/liquid interface and the crystal growth rate. To some alloys, a can be changed from 90°to 0°if the ratio is increased to be higher than a critical value, so the c-axis texture orientation can be obtained. In Nd-Fe-B system, the easy magnetization axis of Nd2Fe14B is always perpendicular to the preferential growth direction [ 100], and the easy magnetization axes of Nd2Fe14B grains are randomly distributed in the plane normal to the growth direction even if the growth rate is decreased from 250 to 12μm·-1. But if the magnetization axis of the anisotropic magnet substrate is perpendicular to the heat flux direction of the laser melting solidification layer, c-axis texture of the columnar Nd2Fe14B grains in the layer can be obtained, which is the same as that of the substrate, if the laser scanning rate is not less than 25μm·s-2. Also the c-axis texture [006] can be achieved through hot-deformation of PrxFe93.5-xB5Cu1.5(x = 15 - 19) under the conditions of hot-pressing temperature 973 ~ 1273 K, strain rate 10-3 S-1, and strain 50% ~ 80% .
基金Supported by the National Natural Science Foundation of China under Grant Nos 11374010 and 11434009the Fundamental Research Funds for the Central Universities
文摘Using in situ electric-field-modulated anisotropic magnetoresistance measurement, a large reversible and non- volatile in-plane rotation of magnetic easy axis of -35° between the positive and negative electrical poling states is demonstrated in C040Fe40B20//（001）-cut Pb（Mgl/3Nb2/3）O3-25PbTiO3 （PMN-PT）. The specific magneto- electric coupling mechanism therein is experimentally verified to be related to the synchronous in-plane strain rotation induced by 109° ferroelastic domain switching in the （001）-cut PMN-PT substrate.
基金The authors are grateful for financial support from the National Natural Science Foundation of China(No.50931002)and the National Basic Research Program of China(973 Program,No.2007CB-936601).
文摘Slanted Fe nanorods prepared by glancing angle deposition on silicon substrates exhibited easy magnetization along their growth axis. By using a thin gold film on a silicon substrate as a buffer layer, slanted Fe nanorods can be realigned towards the substrate surface normal by a strong magnetic field. After realignment, the Fe nanorods retained the easy magnetization axis along their growth axis. The effects of the realignment by the strong magnetic field on the properties of the slanted Fe nanorods were also investigated. This study provides a possible way to fabricate magnetic nanostructures for perpendicular recording applications.
