热处理温度对FeCoSiB薄膜及FeCoSiB/Cu/FeCoSiB三明治膜应力阻抗效应的影响

采用DC磁控溅射法在玻璃基片上制备了FeCoSiB薄膜和FeCoSiB/Cu/FeCoSiB 三明治膜,并进行磁场退火热处理以消除残余应力和形成磁织构,提高薄膜的应力阻抗效应。薄膜的磁性能采用振动样品磁强计(VSM)进行测试,采用HP4275A 型阻抗分析仪在200kHz~10MHz频率范围内测试薄膜的应力阻抗效应。结果表明,磁场退火热处理可形成感生磁各向异性,改善薄膜的软磁性能、提高薄膜的应力阻抗效应。在温度低于300℃时,随着退火温度的增加,薄膜的应力阻抗效应增大;当退火温度超过300℃时,薄膜的应力阻抗效应随退火温度增加而降低。与Fe CoSiB单层膜相比, FeCoSiB/Cu/FeCoSiB 三明治膜应力阻抗效应较大。10MHz测试频率下,在基片末端位移为450μm时,经300℃热处理的三明治膜达到了8.3%,而单层膜仅有1.86%。当测试频率较高为10和4MHz时,薄膜的应力阻抗效应变化不大,当测试频率下降到低于1MHz时,薄膜的应力阻抗效应显著降低。     

柔性FeCoSiB非晶磁弹性薄膜的应力阻抗效应

采用直流磁控溅射方法在柔性Kapton基片上沉积了FeCoSiB薄膜,研究了偏置磁场、溅射气压以及测试频率对薄膜应力阻抗效应的影响规律.结果表明,本文中优化的溅射气压为1.5 Pa,强的偏置磁场可形成强的横向各向异性,从而显著提高材料的应力阻抗效应.随着测试频率从0.1MHz升高到30 MHz,薄膜的应力阻抗效应显著增强.     

张应力对FeCoSiB非晶薄膜磁特性的影响

采用磁控溅射方法,在弯曲的玻璃基片上制备出受张应力作用的FeCoSiB非晶薄膜,研究了张应力大小对FeCoSiB薄膜的磁畴、矫顽力、剩磁、各向异性场等磁特性的影响.结果表明,薄膜的畴结构显著依赖于张应力,其磁畴宽度随张应力增加而增加;张应力导致FeCoSiB薄膜内形成较强的磁各向异性,其各向异性随应力的增大而增大.     

夹心结构FeNi/Cu/FeNi多层膜巨磁阻抗效应研究

采用MEMS技术在玻璃基片上制备了夹心结构FeNi/Cu/FeNi多层膜,并在1～40MHz范围内研究了它的巨磁阻抗效应.纵向巨磁阻抗效应先随着外加磁场的增大而迅速增加,在某一磁场下达到最大值后随磁场的增加而逐渐减小.在频率为5MHz时,Hext为0.8kA/m时巨磁阻抗效应最大值达到32.06%.另外,夹心结构多层膜表现出较大的负巨磁阻抗效应,在频率5MHz,Hext=9.6kA/m时,负最大巨磁阻抗效应可达-24.50%.     

三明治结构FeNi/Cu/FeNi多层膜巨磁阻抗效应研究

采用MEMS技术在玻璃基片上制备了三明治结构FeNi/Cu/FeNi多层膜,在1～40 MHz范围内研究了FeNi/Cu/FeNi多层膜中的巨磁阻抗效应特性.当磁场Ha施加在薄膜的长方向时,巨磁阻抗效应随磁场的增加而增加,在某一磁场下达到最大值,然后随磁场的增加而下降到负的巨磁阻抗效应.在频率为5MHz时,巨磁阻抗效应在磁场Ha=800 A/m时达到最大值26.6%.巨磁阻抗效应的最大值及负的巨磁阻抗效应与多层膜中磁各向异性轴的取向及发散有关.另外,当磁场施加在薄膜的短方向时,薄膜表现出负的巨磁阻抗效应,在频率5 MHz、磁场Ha=9600 A/m时,巨磁阻抗效应可达-15.6%.     

应力生长FeCoSiB非晶薄膜的磁各向异性研究

采用应力生长方法，制备出受压应力和张应力作用的FeCoSiB非晶磁弹性薄膜，研究了薄膜中的应变大小对FeCoSiB薄膜的磁滞回线、剩磁、应力诱导各向异性场等磁特性的影响．结果表明，无应变薄膜在薄膜面内呈现各向同性，而有应变的薄膜呈现出明显的各向异性。张应力诱导的各向异性与应力方向平行，而压应力形成垂直于应力方向的磁各向异性。各向异性场随应变的增大而线性增大。     

弯曲型三明治结构FeCuNbCrSiB/Cu/FeCuNbCrSiB多层膜巨磁阻抗效应研究

利用磁控溅射方法及微细加工技术制备了弯曲型三明治结构的FeCuNbCrSiB／Cu／FeCuNbCrSiB多层膜，在频率1～40MHz下研究了多层膜的纵向和横向巨磁阻抗效应，结果表明弯曲型三明治结构多层膜的巨磁阻抗效应高于它的传统的多层膜。在频率10MHz、磁场11．94kA／m下巨磁阻抗效应达-50%。     

非晶FeCoSiB薄带的压磁性能研究

采用单辊法制备非晶FeCoSiB薄带,并进行退火处理以消除残余应力,提高薄带的压磁效应.采用4294A型阻抗分析仪在40Hz～100MHz频率范围内测试薄带的压磁效应.结果表明,退火可使薄带内部产生磁各向异性,消除内应力,提高薄带的压磁性能.在退火低于300℃时,薄带压磁效应随着退火温度的增加而增加;但当退火温度高于300℃后,薄带压磁效应随着退火温度的增加而降低.当温度为300℃时,退火时间也会对薄带的压磁性能产生影响,在退火时间低于1h时,薄带压磁效应随着退火时间的增加而增加;但当退火温度高于1h后,薄带压磁效应随着退火时间的增加而降低.非晶FeCoSiB薄带的经过300℃×1h退火后,测试频率为100MHz﹑压力为1.42MPa时,阻抗变化可达3.38Ω,压磁性能最佳.     

曲折状FeSiB/Cu/FeSiB三层膜结构应力阻抗效应研究

采用磁控溅射法在玻璃基底上制备了曲折状FesiB／cu／FesiB三层膜结构,在1—40MHz范围内研究了FeSiB膜和Cu膜厚度对三层膜结构应力阻抗效应的影响。结果表明：高频下三层膜的应力阻抗效应随着其形变的增加近似线性增加,在自由端弯曲变形1mm、外加电场频率为25MHz时,应力阻抗效应达到-18．3％,在力敏传感器方面具有广阔的应用前景。     

FeSiB/Cu/FeSiB多层膜巨磁阻抗效应研究

用磁控溅射法在玻璃基片上制备了FeSiB/Cu/FeSiB多层膜,在100kHz～40MHz范围内研究了FeSiB/Cu/FeSiB多层膜中的巨磁阻抗效应特性.当磁场强度Ha施加在薄膜的长方向时,巨磁阻抗效应随磁场的增加而增加,在某一磁场下达到最大值,然后随磁场的增加而下降到负的巨磁阻抗效应.在频率为3.2MHz时,在磁场强度Ha=2400A/m时巨磁阻抗变化率达到最大值13.50%;在磁场强度Ha=9600A/m时,巨磁阻抗变化率为-9.20%.巨磁阻抗效应的最大值及负的巨磁阻抗效应与多层膜中磁各向异性轴的取向及发散有关.另外,当磁场施加在薄膜的短方向时,薄膜表现出负的巨磁阻抗效应,在频率为3.2MHz,磁场强度Ha=9600A/m时,巨磁阻抗变化率可达-12.50%.     

AlN/FeCoSiB磁电复合薄膜的制备及其逆磁电效应研究

借助射频磁控溅射成功制备了AlN/FeCoSiB磁电复合薄膜, 探讨了退火条件对AlN薄膜压电性能和FeCoSiB薄膜磁性能的影响, 并研究了其逆磁电响应。结果显示, 500℃退火处理的AlN薄膜具有高度(002)择优取向和柱状生长结构; 经过300℃退火后FeCoSiB薄膜的磁场灵敏度提高。该磁电复合薄膜的逆磁电电压系数(α_CME)在偏置磁场(H_dc)为875 A/m时达到最大值62.5 A/(m·V); 且磁感应强度(B)随交变电压(V_ac)的变化呈现优异的线性响应(线性度达到1.3%)。这种AlN/FeCoSiB磁电复合薄膜在磁场或电场探测领域具有广阔的应用前景。     

Magnetic anisotropy control in amorphous FeCoSiB films by stress annealing

It is important to control magnetic anisotropy of ferromagnetic materials. In this work, magnetic anisotropy of amorphous FeCoSiB films is controlled by stress annealing. FeCoSiB films are deposited on glass substrate and annealed with stress in vacuum. When the annealed films are released from clamp, permanent tensile or compressive strain can be introduced in the films. Influences of both tensile and compressive strain on the magnetic properties of FeCoSiB films have been studied. The results show that FeCoSiB films by stress annealing exhibit strong magnetic anisotropy while the samples by normal annealing exhibit magnetic isotropy. Easy axis along the stress is induced in the films with tensile stress, while easy axis perpendicular to the stress is induced in the samples with compressive stress. It has also been found that the magnetic anisotropy increases with the increase of the strain. The effects of strain on the magnetic properties of FeCoSiB films have been interpreted by stress induced anisotropy via magnetoelastic coupling.     

FeCoSiB薄膜应力阻抗性能的的影响因素及提高方法

利用磁控溅射方法在玻璃基片上制备了FeCoSiB薄膜，溅射过程中施加一横向静磁场，并在真空中退火。实验结果表明，FeCoSiB的应力阻抗效应与制备工艺（工作气压、溅射磁场）和退火条件（退火温度、退火时间）有着非常密切的联系。当偏置磁场从60 Oe增加到120 Oe时，薄膜的应力阻抗从0．5％提高到了1．65％。在80 Oe磁场下，薄膜经300℃、40min退火处理后，应力阻抗效应达1．86％。     

Effect of metalloids on crystallization and magnetic behaviour of FeCoSiB based metallic glass

A series of amorphous iron-cobalt alloys with varying metalloid, boron and silicon contents were studied for their thermal stability and magnetic behaviour. The crystallization temperature and thermal stability increased with the silicon content. Good soft magnetic properties were observed for the materials with nominal composition, (Fe_0.79Co_0.21)77Si_12.2B_10.8. The magnetic properties were further improved by annealing.     

Structural and optical properties of AlxOy/Pt/AlxOy multilayer absorber

We report on the microstructure and optical properties of Al_xO_y–Pt–Al_xO_y interference-type multilayer films, deposited by electron beam (e-beam) deposition onto corning 1737 glass, silicon (1 1 1) and copper substrates. The structural properties were investigated by Rutherford backscattering spectrometry, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic force microscopy. The optical properties were extracted from specular reflection/transmission, diffuse reflectance and emissometer measurements. The stratification of the coatings consists of a semi-transparent middle Pt layer sandwiched between two layers of Al_xO_y. The top and bottom Al_xO_y layers were non-stoichiometric with no crystalline phases present. The Pt layer is in the fcc crystalline phase with a broad size distribution and spheroidal shape in and between the rims of Al_xO_y. The surface roughness of the stack was found to be comparable to the inter-particle distance. The optical calculations confirm a high solar absorptance of ∼0.94 and a low thermal emittance of ∼0.06 for the multilayer stack, which is attributed not only to the optimized nature of the multilayer interference stacks, but also to the specific surface morphology and texture of the coatings. These optical characteristics validate the spectral selectivity of the Al_xO_y–Pt–Al_xO_y interference-type multilayer stack for use in high temperature solar-thermal applications.