Electron states and the spin density wave phase diagram in Cr(1 1 0) films
Electron states and the spin density wave phase diagram in Cr(1 1 0) films
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Cr(1 1 0) 薄膜中的电子态和自旋密度波相图
DOI：
10.1088/1367-2630/7/1/114
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发表时间：
2005
影响因子：
3.3
通讯作者：
S. Kevan
中科院分区：
文献类型：
--
作者：
E. Rotenberg;B. Freelon;H. Koh;A. Bostwick;K. Rossnagel;A. Schmid;S. Kevan
铬薄膜提供了一个很好的系统来研究尺寸限制对大块材料中观察到的自旋密度波（SDW）基态的物理性质的影响。由于铬是薄膜磁性结构的常见成分，这些特性在技术上也具有一定的重要性。我们在具有楔形厚度的W（11）衬底上制备了高结晶质量的铬（11）薄膜，以便系统地研究约束的影响。我们使用低能电子衍射和显微镜以及高分辨率角分辨光谱学的组合来表征这些薄膜。我们探测了与SDW基态相关的费米曲面及其嵌套向量。我们发现这些可以准确地预测观测到的体SDW周期。我们还通过测量后折叠带之间的分裂直接表征了薄膜中的SDW周期性，我们发现在较高温度下，这种周期性明显偏离了较薄薄膜的体周期性。我们系统地绘制了SDW不可通约性和相图作为膜厚度和温度的函数。我们发现相称和不相称的阶段被几乎连续的过渡所分隔。我们的研究结果提出了一个简单的模型来解释相称相和不相称相之间微妙的相互作用，涉及SDW稳定能量与表面和界面能量之间的平衡。
Chromium films offer an excellent system to study the impact of dimensional confinement on physical properties associated with the spin-density-wave (SDW) ground state observed in bulk materials. These properties are also of some technological importance since chromium is a common component of thin film magnetic structures. We prepared chromium (1 1 0) films of high crystalline quality on a W(1 1 0) substrate with a wedge-shaped thickness profile so that the impact of confinement can be systematically studied. We have characterized these films using a combination of low-energy electron diffraction and microscopy as well as high-resolution angle-resolved photoemission spectroscopy. We have probed the Fermi surface and the nesting vectors therein that are relevant to the SDW ground state. We find these to predict accurately the observed bulk SDW periodicity. We have also characterized the SDW periodicity in the film directly by measuring the splitting between backfolded bands, and we find that this periodicity deviates markedly from the bulk periodicity for thinner films at higher temperatures. We have systematically mapped the SDW incommensurability and phase diagram as a function of both film thickness and temperature. We find commensurate and incommensurate phases that are separated by nearly continuous transitions. Our results suggest a simple model to explain the delicate interplay between commensurate and incommensurate phases that involves a balance between SDW stabilization energy and surface and interface energetics.
自旋涨落材料的电动力学
DOI：
--
发表时间：
2007
期刊：
影响因子：
--
作者：
V. Stankevich;S. Kimura;他8名;T. Ito;S. Kimura
通讯作者：
S. Kimura