Investigation of Magnetotransport Phenomena in Half Metallic CrO2

半金属 CrO2 磁输运现象的研究

• 批准号: 10650032
• 负责人: SUZUKI Katsuhiko
• 金额: $ 2.24万
• 依托单位: Miyagi National College of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650032/
• 关键词: Half Metal; X-Ray Diffraction; Thermal Treatment; Co-Tunneling; Magnetoresistance; CVD; Quantized Energy Level; Distortion of Crystal Structure; CrO_2; 電気抵抗; 磁気抵抗; 強い電子相関効果; 単結晶

(1) It was found that the CrO2 film is selectively deposited onto the patterned TiO2 film by the thermal oxidation of the Ti film on the glass substrates in terms of CVD method. The tunnel junction was made using the technique. Although the value of tunnel resistance was adequate, the TMR properties did not show the good data. The properties may be improved by making the interface between the CrO2 film and insulator smooth.(2) The resistivity and magnetoresistance of the CrO2 film with only (100) texture on the ZrO2 substrate were measured in the wide temperature range up to 10T.The shape of the temperature dependence of resistivity can be interpreted by the description of the half metal and the relation of the values of the coefficient of T^2 dependence and electronic specific heat suggested the CrO2 belongs to the group of the heavy fermion. The value of the parameters obtained by the analysis of the data of the magnetoresistance contain the information on the mean free path and they … More suddenly increased below about 5K, which shows the lack of spin flip scattering process by magnon excitation because of the half metal.(3) The magnitude of the negative magnetoresistance of (100) CrO2 film on TiO2/Si (111) with (110) orientation was larger than that of (100) film on ZrO2 substrate.(4) By the annealing at 473K, the magnitude of the negative magnetoresistance (MR) of the CrO2 film on TiO2/glass became large above about 20K, while the magnitude small below about 20K.The lattice spacing of a-axis was extented by the annealing at 473K.The band calculation and WKB approximation suggest that the magnitude of MR becomes by this extension.(5) The staircase pattern in magnetic field dependence in magnetoresistance was found. The step height of the staircase was constant under a constant current and reciprocal to the current, which means that the steps change at each the constant voltage interval. These phenomena can be interpreted by co-tunneling of the multi-tunnel junctions contained in the films. Less

（1）发现CRO2膜通过CVD方法在玻璃基板上的Ti膜的热氧化选择性地沉积在图案化的TiO2膜上。使用该技术进行隧道交界处。尽管隧道电阻的值足够，但TMR性质并未显示出良好的数据。可以通过使CRO2膜和绝缘子之间的接口平滑地进行界面来改善。（2）在ZRO2底物上仅具有（100）纹理的CRO2膜的耐药性和磁性在宽温度范围内测量到10T，最高为10T。电阻的温度依赖性以及crol the crol the crol the crol the croct of the Crol the Crol the Crol the Croce^extor^extor的依赖的依赖的依赖性的依赖性^2属于沉重的费米恩。通过分析包含有关平均自由路径的信息的数据获得的参数的值，它们……突然间，它们突然增加了大约5k，这表明由于半金属而缺乏透明散射过程。 ZRO2底物。（4）通过473K退火，Tio2/玻璃上CRO2膜的负磁倍率（MR）的大小在大约20K上方大于20K，而幅度小于20K，大约20K。A轴的晶格间距扩大了473K的范围。发现磁场依赖性的楼梯图案在磁场抗性中。楼梯的台阶高度在恒定电流下是恒定的，并且与电流相等，这意味着每个恒定电压间隔在每个恒定电压间隔变化。这些现象可以通过胶片中包含的多孔连接的共同隧道来解释。较少的

项目成果

K.Suzuki and P.M.Tedrow: "Longitudinal Magneto resistance of CrO_2 Thin Films"Applied Physics Letters. 74. 428-429 (1999)

K.Suzuki 和 P.M.Tedrow：“CrO_2 薄膜的纵向磁阻”应用物理快报。

K.Suzuki and P.M.Tedrow: "Longitudinal Magnetoresistance of CrO_2 Thin Films" Applied Physics Letters. Vol.74,No.3. 428-429 (1999)

K.Suzuki 和 P.M.Tedrow：“CrO_2 薄膜的纵向磁阻”应用物理快报。

K.Suzuki and P.M.Tedrow: "Selective Deposition of CrO2 Film on Glass Substrates"Solid State Commun.. 107. 583-585 (1998)

K.Suzuki 和 P.M.Tedrow：“在玻璃基板上选择性沉积 CrO2 薄膜”Solid State Commun. 107. 583-585 (1998)

K.Suzuki and P.M.Tedrow: "Resistivity and Magnetotransport in CrO_2 Films" Physical Review B. Vol.58,No.17. 11597-11602 (1998)

K.Suzuki 和 P.M.Tedrow：“CrO_2 薄膜中的电阻率和磁输运”物理评论 B. 第 58 卷，第 17 期。

K.Suzuki and P.M.Tedrow: "Resistivity and Magnetoresistance in CrO_2 Films"Physical Review. B58. 11597-11602 (1998)

K.Suzuki 和 P.M.Tedrow：“CrO_2 薄膜中的电阻率和磁阻”物理评论。