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Rare earth permanent magnets Sm(Co, Fe, Cu, Zr)z with outstanding performance and high-temperature thermal stability were fabricated. Optimized by Fe content and process, Sm(Co0.72Fe0.15Cu0.1Zr0.03)7.5 magnet with B1〉0.75 T and Hci〉1300 kA/m at 300 ℃ can be obtained. According to the performance data of Sm(Co0.72Fe0.15Cu0.1Zr0.03)7.5, the magnetic field along central axis Bz in periodic permanent magnet (PPM) focusing system was simulated using electromagnetic field analysis software Maxwell 2D/3D. The Bz exhibited typical cosine curve along central axis, and the peak value of Bz was high enough to meet the demand of PPM focusing system at room temperature even at 200±20 ℃. Additionally, a kind of simple cooling structure for PPM focusing system was designed by setting cooling pipe between polepieces. Simulated results showed that smooth cosine curve of Bz was successfully achieved with good control of the thickness of cooling pipe. 相似文献
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优化材料性能参数和自旋阀巨磁电阻磁头的结构参数是磁器件实用化的关键。基于建立的物理计算模型,首先将自旋阀巨磁电阻磁头传感单元作为有源磁电阻放入前端放大电路,对输出电压,二次谐波及线性区间进行态模拟发现在宽g1+g2≤0.7μm,线性偏电流10-50mA范围内,自旋阀磁头相对记录介质有线性信号输出。 相似文献
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Ca1-xRxCu3Ti4O12(R=La,Y,Gd;x=0,0.1,0.2,0.3) electronic ceramics were fabricated by conventional solid-state reaction method.The microstructure and dielectric properties as well as impedance behavior were carefully investigated.XRD results showed that the secondary phases with the general formula R2Ti2O7 existed at grain boundaries of rare earth doped ceramics,which inhibited abnormal grain growth.The dielectric constant decreased from 4×105 in pure CaCu3Ti4O12(CCTO) ceramics to 2×103 with rare earth doping.However,all samples showed high dielectric constant in broad frequency range(10 MHz).The cutoff frequency(f0) was remarkably shifted to higher frequency from 13 MHz(pure CCTO ceramics) to 80 MHz(Gd-doped CCTO ceramics).Meanwhile,the dielectric loss tangent rapidly decreased approximately 10 times.These improvements of dielectric properties by rare earth doping are very useful in wide frequency chip capacitor and LTCC devices. 相似文献
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用直流磁控溅射方法制备了NiFe/Cu/NiFe层状薄膜 ,研究了Cu膜宽度对NiFe/Cu/NiFe层状薄膜的巨磁阻抗效应的影响 ,结果表明 ,层状薄膜的巨磁阻抗效应随Cu膜宽度发生振荡现象 ;并提出了一个等效电路模型直观地解释了层状薄膜增强巨磁阻抗效应的机理 相似文献
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