Fabrication of semi-conductor titanium oxide films containing isolated fine iron-based metal particles and measurement of the GMR effect under illumination of UV light

本研究的目的是制造新的功能氧化钛薄膜含有孤立的细铁颗粒，显示巨磁阻（巨磁阻）效应，并确认这种纳米复合薄膜提供增强的巨磁阻效应下的紫外光照射。经过几个改进的溅射室在这项研究中使用，纳米复合薄膜组成的隔离细铁颗粒在基体氧化钛，通过使用钛氧化物板和铁板作为目标。参照诸如沉积条件和退火条件的制备条件，检查晶体结构、光学透明性、电阻、包括磁场下的GMR效应的磁特性。主要溅射条件：输入电功率：50 × 70 W，溅射Ar气压：3 × 6 × 10 - 5 <-3>Torr。通过测量沉积时间手动控制铁颗粒的沉积。然而，在这项研究中， ...更多信息 几个意想不到的机器故障，包括溅射期间不稳定的溅射氩气流和泵送速率，延迟了原计划。主要结果如下：（1）由分散在基体氧化钛中的孤立的细小铁颗粒组成的复合膜在沉积后呈非晶态，但在空气中200℃退火后变成氧化钛的晶态。(2)有些薄膜在室温下具有很小的巨磁电阻，ΔR/R= 0.02%，并且薄膜的透明度随着铁颗粒沉积总量的增加而降低，因此这些薄膜没有表现出任何巨磁电阻。(3)在空气中400℃退火后，具有金属光泽的薄膜变得透明，呈黄色，这可能是锐钛矿型基体钛中的铁颗粒被氧化所致。然而，这些电影没有显示任何GMR。X射线分析没有证实铁氧化物的存在。(4)研究发现，薄膜的透明度、电阻率和磁性能之间的关系对于测量薄膜的磁电阻具有重要意义;光学透明薄膜不可能测量磁电阻，也不具有GMR效应。这也证明了良好的控制制备是非常重要的，以获得最佳的纳米复合薄膜，在一个可测量的范围内的巨磁电阻。经过几次改进，目前的实验失败，我们将尝试提高GMR效应的紫外光照射下，通过各种制造工艺，包括溅射Ar和N2气体的混合比例。少

The objects of this research are to fabricate new functional titanium oxide films containing isolated fine iron particles which show the GMR (giant magnetic resistance) effect, and to confirm that such nanocomposite films provide enhancement of the GMR effect under illumination of UV light. After several improvements of the sputtering chamber used in this study, nanocomposite films composed of isolated fine iron particles in the matrix titanium oxide were fabricated by using titanium oxide plate and iron plate as a target. The crystal structure, optical transparency, electrical resistance, magnetic properties including the GMR effect under a magnetic field were examined with reference to preparation conditions such as deposition conditions and annealing conditions. Main sputtering conditions : in-put electric power ; 50〜70W, sputtering Ar gas pressure ; 3〜6 x10^<-3> Torr. The deposition of iron particles was manually controlled by measuring deposition time. During this study, however, … More several unexpected machine troubles including unstable sputtering argon gas flow during sputtering and pumping rate delayed the original plan. The main results are : (1) Composite films composed of isolated fine iron particles dispersed in the matrix titanium oxide showed amorphous state after deposition, but after 200℃ annealing in air they became crystalline state of titanium oxide. (2) Some films provided a very small GMR, ΔR/R=0.02%, at room, and the transparency of the films decreased with increasing total deposition amount of iron particles and thus such films did not show any GMR. (3) After 400℃ annealing in air, the films showing metallic brightness became transparent and yellow-like, probably because of oxidization of iron particles in the anatase-type matrix titanium. The films, however, did not show any GMR. X-ray analysis did not confirm the existence of iron oxides. (4) A relationship among transparency, resistance and magnetic property was found to be important for measuring the magnetoresistance of fabricated films ; Optically transparent films proved to be impossible to measure the magnetoresistance and provided no GMR effect. It also proved that the well-controlled fabrication is very important to get optimum nanocomposite films which are in a measurable range of the GMR. After several improvements of the present experimental failures, we will try to enhance the GMR effect under illumination of UV light through various fabrication processes including a mixture ratio of sputtering Ar and N2 gases. Less