Electronic structures and creation of new function of bulk and nano-materials with shape memory property

具有形状记忆特性的块体和纳米材料的电子结构和新功能的创造

基本信息

批准号：
13640368
负责人：
ISHIDA Shoji
金额：
$ 0.7万
依托单位：
Kagoshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

Theoretical results.To use shape memory alloys (SMA) in wide temperature region, it is important to control the phase transition temperature (PTT). The PTT of ferromagnetic SMA Ni-Mn-Ca-X (X=transition elements) was predicted theoretically on the basis of electronic states. Investigations to control PTT have also been done for TiNi-based alloys by adding the third elements (X atoms). The site preference of X atoms was examined and it was predicts that Fe and Co atoms prefer the Ni site and Cu and Zn atoms the Ti site. The electronic structures of films of Ni_<2.17>Mn_<0.83>Ga, TiNi, TiNi_<8/9>Fe_<1/9> were calculated and the characteristics were clarified.Experimental results.In order to make thin films of shape memory alloys by using sputtering processes, we clarified following points; effects of argon gas flow in transfer processes of sputtered particles, control of the thin film composition with very high accuracy by introducing the second attachment probability of sputtered particles and collision process of sputtered particles in surface boundary layer on the rotating substrate. Control of the fine structures in thin films was impossible due to the high energy irradiation from plasma. For developing new nanostructured devices with shape memory alloys, it is very important to decrease the energy of sputtered particles. To evaluate the electron states in half-metallic oxides thin films, spin polarized electron spectroscopy with high accuracy was developed.

理论结果。为了在宽温度范围内使用形状记忆合金（SMA），控制相变温度（PTT）非常重要。根据电子态对铁磁 SMA Ni-Mn-Ca-X（X=过渡元素）的 PTT 进行了理论预测。通过添加第三种元素（X 原子），还对 TiNi 基合金进行了控制 PTT 的研究。检查了 X 原子的位点偏好，预测 Fe 和 Co 原子更喜欢 Ni 位点，而 Cu 和 Zn 原子更喜欢 Ti 位点。计算了Ni_<2.17>Mn_<0.83>Ga、TiNi、TiNi_<8/9>Fe_<1/9>薄膜的电子结构并阐明了其特性。实验结果。为了制备形状记忆薄膜通过使用溅射工艺制备合金，我们阐明了以下几点；研究了溅射粒子传输过程中氩气流的影响、通过引入溅射粒子的二次附着概率以及溅射粒子在旋转衬底表面边界层中的碰撞过程对薄膜成分进行高精度控制。由于等离子体的高能辐射，控制薄膜中的精细结构是不可能的。为了开发具有形状记忆合金的新型纳米结构器件，降低溅射粒子的能量非常重要。为了评估半金属氧化物薄膜中的电子态，开发了高精度自旋极化电子能谱。