激光调制交流测量高温热电势

本文设计了一种交流法测量室温到1200K的热电势的实验装置。与传统的直流测量方法相比，这一方法有许多优点：方便、适合小样品、能够测量单晶的各向异性，可以连续的测量热电势对温度的依赖关系。为了检验这一新方法的可靠性和准确性，我们测量了纯Pt丝的热电势。     

电荷密度波材料NbSe3高温隧道谱的意外发现

对NbSe     

Compositional Dependence of Electronic Specific Heat in AlCuCo Decagonal Quasicrystals： Evidence for the Hume-Rothery Mechanism of Phase Formation

There is no consensus whether the electron density of states of decagonal quasicrystals has a pseudogap at the Fermi energy similar to that of the icosahedron phase. We answer this question by measuring the electronic specific heat coefficient of AlCuCo decagonal single-quasicrystals over a wide range of composition. While the average valence electron number per atom, e/a, for all the resultant samples changes only within 1.5%, from-1.92 to less than 1.95. The specific heat coefficient decreases by 15% with the increasing e/a. The large change and the negative slope give strong evidence for Hume-Rothery mechanism of the decagonal phase.     

AlNiCo D相准晶的隧道发现丰富的尖峰结构

在对ＡｌＮｉＣｏ Ｄ 相准晶的极低温下的隧道测量中发现了丰富的尖峰结构     

顶端加载、温度范围在300～1.4K的多功能交流测量恒温器

本文介绍了一台用于交流小讯号测量的低温恒温器.利用内液池减压,最低温度可达1.370K,并且在测量功率为0.15mW时,内液池液氦可以维持样品温度在1.4K达20小时以上.系统装置了在8T的背景磁场内最高可达0.18T的交变调制场,从而可以实现利用双交流法精细测量磁阻或霍耳系数随磁场变化的函数关系.试验结果表明,此恒温器具有低液氦蒸发量和可从1.3～300K连续控温的特点.用此装置对Co膜的霍尔系数测量的实验中,霍尔电压变化量的测量精度达到了0.5nV.     

Growth of High-Quality Decagonal Al-Cu-Co Quasicrystals from Ternary Melt

By changing the initial elements, we obtain high-quality samples of Al-Cu-Co decagonal quasicrystals with a wide range of composition. The sizes of the samples are typically several centimetres in length and 2-3 mm in diameter. These samples are identified to be decagonal single grains by powder x-ray diffraction method, and the composition is homogeneous confirmed by EDX and chemical method.     

Temperature-driven spin reorientation transitionof magnetron sputtered nickel thin film

The temperature-driven spin reorientation transition of magnetron sputtered Ni/Si （111） systems has been studied. The relationship between ac initial susceptibility and temperature of nickel films with different thicknesses shows that the magnetization orientation changes from in-plane to out-of-plane with the increase of temperature. The temperature dependence of mugnetoelastic, magneto-crystalline, and magnetostatic anisotropies determines the direction of the reorientation transition. The temperature-driven spin reorientation transition is supported by Hall coefficient measurements which show that its temperature dependence is similar to that of susceptibility.     

电荷密度波材料NbSe3高温隧道谱的意外发现

对ＮｂＳｅ３在第一相变温度上下的隧道谱测量,意外地发现在通过电荷密度波（ＣＤＷ）相变温度时电子态度没有反常。首次直接证明在远高于相变温度处赝能隙已存在。     

D相准晶显示强烈的各向异性电—声子质量增强效应

对ＡｌＮｉＣｏＤ相准晶和热电势测量表明，沿准晶面的电－声子质量增强效应比沿周期方向要大一个数量级以上。     

非晶态TbFe_2薄膜的磁性和电性

本文研究了TbFe_2非晶态薄膜的磁性和电性,测量了M_s(T)(77—800K),ρ(T)(4.2—400K)和穆斯堡尔谱(18K,400K),得到居里温度T_c～400K,电阻极小值温度T_(min)～360K,在T<360K范围内观察到温度系数为负的类Kondo效应,用 Hesse和Window两种不同方法解出了室温穆斯堡尔谱的超精细场,得到了H=210kOe和H=25kOe两种分布,其中前一组给出了铁磁性,后一组可能与类Kondo型电阻反常有关,实验结果还表明,铁离子自旋受很强的局域各向异性场作用,这和Harris模型相符。